and i do love her still. josh mankiewicz (voiceover): you got a lot of life left, a lot. how are you going to live it? to the best of my abilities. josh mankiewicz (voiceover): there are jurors who think he might have done it, but i had reasonable doubt. i couldn't vote to convict. well, god bless him. but there's a lot of people that do believe in me. josh mankiewicz (voiceover): he's made his own peace with a simple truth, the very thing that freed him, reasonable doubt, could also shadow conrad truman for the rest of his life. that's all for this edition of "dateline." i'm andrea canning. thanks for watching. . i'm craig melvin. and i'm natalie morales. and this is "dateline." at night, this is absolutely pitch dark. it was abandoned, and it was secluded. this was his playground.

this was the place that we've been searching for. craig melvin (voiceover): it was the still of the night when the killing started. you can feel and hear the fear in her voice. craig melvin (voiceover): a single mother and her teenage daughter ambushed in their bedrooms. here comes a monster into your house. i just broke down, you know? i just couldn't imagine who would want to do this. craig melvin (voiceover): then, it happened again to another mother, another daughter. dennis murphy: somebody's killing mothers and daughters. that's about as scary as it gets. scary as it gets. craig melvin (voiceover): who was out there? and who would be next? something you would never imagine would happen. craig melvin (voiceover): the clues would lie here, an abandoned mansion, eerie, haunting. where was this killer hiding? cold, calculating eyes. lifeless. he was almost a ghost. craig melvin (voiceover): could they catch him? could they stop him?

i get chills all over. i'm kind of on the edge of my seat. he truly thought he could outsmart us. hello, and welcome to "dateline." would you recognize danger if it was lurking nearby? this story that you're about to hear is a tale of true terror. a killer was stalking victims in a quiet neighborhood, leaving residents panicked that they would be next. police were determined to catch him, unaware he was hiding in plain sight. but soon, a stolen set of keys would help investigators unlock this mystery and unmask a murderer. here's dennis murphy with "the unusual suspect." dennis murphy (voiceover): consider for a moment that cozy word "home" and all it evokes-- warmth, family, shelter, security.

got it? and now reflect on what happens when those four walls are breached, when nightmare stuff crawls through the window, kicks in the doors, when a haven becomes a house of horrors. so how does that feel? just ask lloyd irvin. i'm laying on the couch. i wake up, and there's two gunmen over top of me, holding guns, pointing them at me, like, holding down. you're being robbed. don't move. dennis murphy (voiceover): years have passed since that night in august 2008 here outside the nation's capital in a nice neighborhood in prince george's county, maryland. but lloyd and viki irvin and their son, just four years old at the time, are still haunted by the image of the gunmen, two masked intruders. talk about worst nightmares. this is it. yes, something you would never imagine would happen. dennis murphy (voiceover): what the robbers didn't count on was that lloyd is a nationally renowned martial arts expert. and when one of the gunmen walked away to scope

out the rest of the house, lloyd was suddenly one on one with his accomplice. gunman's over here in the corner, huh? right in the corner, right there. i know he doesn't have any room to back up at all. and i just go. i'm coming over here. i got the gun. i'm trying to get the cartridge out. and once i get the cartridge out, it drops. so i hit the ground. dennis murphy: and where's the intruder gone? he ran out the room. he was running a little like, he has the gun. get out of here. he has the gun. dennis murphy (voiceover): by the time lloyd managed to reload the wrestled away gun and give chase, both home invaders had escaped. and i'm calling 911, and i'm just-- my son's on top of me. and he's just shaking, not saying a word, not crying, just shaking. and i often think, you know, were they going to kill us that night? dennis murphy (voiceover): the irvin family wouldn't be the first or the last to ask that awful question. dennis murphy (voiceover): in the months that followed, the area was hit with a wave of home invasions. each time, two masked men, meticulous about not

leaving fingerprints or evidence behind. the prince george's county police were baffled, the community understandably on edge. and then, on january 26, 2009, on a quiet street in upper marlboro, the county seat, anxiety turned to full-on "bolt the doors" panic. dennis murphy (voiceover): it was a desperate plea for help from a dying girl. on the phone, 16-year-old student karissa lofton. dennis murphy (voiceover): police rushed to the scene, but it was too late. they found karissa and her mom karen in their bedrooms, each killed execution style with a shot straight to the head. crimes quickly become statistics, but this just stands out, doesn't it? it stands out. it makes the hair on the back of your neck stand up also. dennis murphy (voiceover): veteran prince george's

county homicide detective bernie nelson was in charge of the case. the first arriving officers told him they'd found the main door locked shut from the inside. the killer, they thought, had likely entered the house through an unlocked side window. this bedroom on the second floor that's facing us, that's where karissa was found. dennis murphy (voiceover): detective nelson wondered, did the murders have anything to do with the plague of recent home invasion robberies? if so, why was nothing stolen from the house? her vehicle was still in the driveway. nothing appeared disturbed. dennis murphy (voiceover): investigators didn't find any useful forensic evidence, just six spent shell casings from the bullets that had killed karen and carissa, fired from a glock 17 handgun. we did find out that just two doors down, across the street, someone had seen a blue vehicle parked on the right side of the road. and that, right now, at this point, that's all i have. dennis murphy (voiceover): so detective nelson set out to find out more about his victims.

karen lofton turned out to be a devoted mother and nurse with no apparent enemies. she was divorced from karissa's father, kirkland, who now lived in atlanta. the daughter, karissa, was in private school, good grades, and still very attached to her father. karissa was a special girl for me because at a young age, she had open heart surgery. and she bounced right back from it. dennis murphy (voiceover): kirkland says he had watched karissa blossom into a gregarious teenager, a fashionista and aspiring model with a knack for selfies. i sing this song by bob carlisle. it was called "butterfly kisses." it told the story of him and a daughter. i used to sing that song to her, and she would just look up at me. and she just loved me singing that song to her. she was my butterfly. that's what i called her. dennis murphy (voiceover): now kirkland's butterfly was dead. and detective nelson recruited some of pg county's finest

to help him solve the case, including then detective anthony schartner. this is, you know, a mother, hardworking, and her daughter. you know, both think that they're safely inside their home. and here comes the guy out of your worst dreams. yep, here comes a monster into your house. and he's got a glock. it shocked us all. dennis murphy (voiceover): as the hunt for this brutal killer went into full gear, detectives started, as they always do, with the usual suspects. since there was no rhyme or reason behind it that you can come up with, you have to look at family members. dennis murphy (voiceover): and one family member in particular, karissa's 20-year-old brother keon. he lived in the house, too, but he wasn't there when cops arrived. police spotted him near the crime scene several hours after the murders. could a son, a brother, have done such a monstrous thing? the investigation begins with some tough questions for keon. craig melvin (voiceover): coming up.

one of the detectives blatantly said, everybody in that room thinks it's you. craig melvin (voiceover): was it? what happened next would launch the whole new wave of fear, when "dateline" continues. protect against rsv with arexvy. arexvy is a vaccine used to prevent lower respiratory disease from rsv in people 60 years and older. arexvy does not protect everyone and is not for those with severe allergic reactions to its ingredients. those with weakened immune systems may have a lower response to the vaccine. the most common side effects are injection site pain, fatigue, muscle pain, headache and joint pain. arexvy is number one in rsv vaccine shots. rsv? make it arexvy. icy hot. ice works fast. ♪♪ heat makes it last. feel the power of contrast therapy. ♪♪ so you can rise from pain. icy hot.

what if your mobile network wasn't just built to so yo work out here...ain. ...but was designed differently to also give you blazing fast wifi where you are most of the time? reliable 5g, plus wifi speeds up to a gig where you need it most. xfinity mobile. xfinity internet customers, ask how to get a free 5g phone and a second unlimited line free for a year. the future of cool, comfortable sleep is here. introducing the new sleep number climate cool smart bed. the only smart bed in the world that actively cools and effortlessly adjusts to both of you. sleep up to 15 degrees cooler on each side. it actively cools by drawing warm air away from your body,

to keep you cool and comfortable throughout the night. our smart sleepers get 28 minutes more restful sleep per night. it's our lowest price of the season on our most popular smart bed. save $1,000 plus free home delivery with an adjustable base. shop a sleep number stor dennis murphy: a mother and her daughter executed. detective bernie nelson had investigated hundreds of murders, had learned to keep the recurring images

of death at arm's length. but this case was different. he was a father to a teenager around karissa lofton's age. karissa lofton (on phone): ma'am, i've been shot. me and my mother have been shot. i'm bleeding to death. that poor little girl in her bedroom. she has the gumption to get on the phone and call you. it hurts to listen to listen to the 911 one call because you can-- you can feel and hear the fear in her voice. dennis murphy: even though nothing was taken, it seemed clearer that the killer broke into the house. in fact, the burglar alarm had gone off. but it was disabled in under a minute. and that put karen's son, keon lofton, at the top of police's person-of-interest list. he lived in the house. he knew the code. police brought him in for questioning. one of the detectives blatantly said, everybody in that room thinks it's you. you know, you're the only one who had access to the pin code.

i was upset. like, [inaudible] is me. but i didn't have anything to do with it, you know. you can do whatever you need to do. it's not going to be me. dennis murphy: keon told investigators he'd been spending the night at his fiancee's house when her mom woke him and told him she'd heard on the news that two women on his street had been murdered. i just ran out the house. my heart's racing. i just hopped the gate, hopped in my car. i'm running lights. i'm speeding. i'm still calling at the same time. and when i got there they asked me for my name. and i-- and i was like, i'm keon. and the police officer just kind of looked into his radio and said, ok, we got this son here. and i just-- i just broke down. dennis murphy: keon's alibi checked out. it wasn't him. investigators also interviewed kirkland, karen's ex-husband and karissa's father. he, too, had an airtight alibi. he'd been in atlanta at the time of the murders. bernie nelson: you go a lot of places together? dennis murphy: next on detective nelson's list was karen's former boyfriend, michael lacey.

he'd refused to take a lie detector test. so police interviewed him three separate times. he's someone that we had to rule out completely. and we did that. so if you're thinking in your line of work, the usual suspects, the usual suspects weren't going to figure in this one. not as far as immediate family. dennis murphy: detectives nelson and schartner realized they had on their hands what homicide cops hate, a true mystery. the first 48 hours of the case, usually you get a break in here. there's something that says chase this, right? yes, normally, you would get something within the first 48 hours. so this thing was as baffling as it was cruel. exactly. it doesn't make any sense. dennis murphy: then came march 16, 2009, six weeks after the lofton killings, when two unsolved murders became four. it began with a report of a stolen nissan maxima just a couple of blocks from where

the loftons had been killed. dennis murphy: detective schartner was on call that night. she's on the phone with the call taker. she notices that her car comes zooming by from up here on the street and comes by her at a fast rate of speed. she sees it while she's on the phone with dispatch? here it comes. there it goes. absolutely. dennis murphy: police swarmed the neighborhood, hoping to nab the car thief. he was nowhere to be found. but police soon discovered the stolen car. captured here on a cruiser's dash camera, it was parked in the driveway of a vacant house, engulfed in flames. firefighters called to the scene to extinguish the fire made a grisly discovery, two bodies burned beyond recognition. and the victims? another mother and her teenage daughter. reporter: dental records confirm the identities of the two

female bodies found monday in the trunk of this stolen car, 42-year-old delores dewitt and her daughter, 19-year-old ebony dewitt. she worked at a nursing home. and she loved taking care of the elderly population. i mean, she loved those people, and they loved her. dennis murphy: patricia smith remembers her sister, deloris, as a mother and nurse who worked hard to provide a good life for her two daughters, but always saved a little time for herself. she liked to go places. every year, she would treat herself on vacation. she felt like she worked hard. she should play hard. dennis murphy: and ebony? she was the live wire at family get-togethers. she just would just make the party laugh and just act crazy until the end of the day. i mean, she-- she loved life. dennis murphy: the last person known to have seen ebony alive was her boyfriend. he told detectives that the previous night they'd had a late dinner. she was wearing her favorite blue sweater. then he drove her home, watched her go inside her house.

the killer may have been waiting. and now when police, once again, made no arrest within 48 hours of the murders, waiting, too, was a devastated patricia. i started going back to my sister's house. late at night, i would go and sit in the yard, just hoping that he would come back. i would sit there with the knife in my hand. and i will hold-- i will hold it real tight, just in case he came up on me or something, because it would be him or me, either him or me. and i told detectives what i did. she couldn't sit still and do nothing. she wanted to be involved in the investigation from day one. she would actually go door to door in the neighborhood and talk to neighbors, try to ask them questions. but i had repeatedly explained to her that we can't have her interrupting our case. she's a thorn in your side. she is. but i understood.

because if my sister were killed, it would be hard for me to sit still, too. dennis murphy: so detective schartner made patricia a promise. we were sitting in the car. and i remember just crying and crying and crying. and then he promised me. he said, i'm gonna get him if it's the last thing i do. he said, i'm gonna get him. dennis murphy: to do that, detectives schartner and nelson had to confront a terrifying question. so you got two murdered mother/daughters within-- across the fence, virtually, same neighborhood. right. so you're thinking, are these things related, right? you have to think that. and if they are related, you have a serial murder on your hands, and you don't know when he's going to hit next. and you don't know who he's going to hit next. craig melvin: coming up, a neighborhood on edge, police under pressure, and the question everyone feared, would there be another victim? it was wide open. we had nothing. that's when it gets scary. craig melvin: when "dateline" continues.

60% of women experience leaks with bladder protection pads. try always discreet! it has a unique core that converts liquid to gel and bunches 25% less often than poise. try always discreet! it's designed to protect. still congested? —nope! —uh oh. new mucinex 2-in-1 saline nasal spray. spray goodbye. aaaaaaahhhhh! new mucinex 2-in-1 saline nasal spray with a gentle mist and innovative power-jet. spray goodbye to congestion.

it's comeback season! protect against rsv with arexvy. arexvy is a vaccine used to prevent lower respiratory disease from rsv in people 60 years and older. arexvy does not protect everyone and is not for those with severe allergic reactions to its ingredients. those with weakened immune systems may have a lower response to the vaccine. the most common side effects are injection site pain, fatigue, muscle pain, headache and joint pain. arexvy is number one in rsv vaccine shots. rsv? make it arexvy.

[coughing] hi susan, honey? yea. i respect that, but that cough looks pretty bad. try this robitussin honey. the real honey you love, plus the powerful cough relief you need. mind if i root through your trash? robitussin, with real honey & elderberry.

dennis murphy: prince george's homicide detectives bernie nelson and tony schartner hoped their collective experience would help crack two of the most horrific murder cases they've ever encountered. when you back up and look at what you got, the scary fact is somebody's killing mothers and daughters, right? that's the commonality. yes. and with the close proximity of where the dewitts were found burned in the vehicle, it was just two blocks away from where the loftons

was shot in their house. dennis murphy: the detectives suspected they were dealing with the same murderer in both cases, especially when they realized delores dewitt was a single mom and a nurse, just like karen lofton. but first they exhausted the usual suspects. delores had an ex-husband and an ex-girlfriend. but both had solid alibis. we'd given them polygraph tests. they passed. we did background checks on them. we found out where they were. and there was nothing that would lead us to say that they were involved. dennis murphy: as in the lofton case, when detective searched that dewitt's home, they found no sign of a forced entry, just an unlocked side window. and inside the house, once again, no forensic evidence, but a different pattern. the killer had taken his victims with him. we don't know if they were killed inside the house and transported away, or if they were just transported away and killed elsewhere. dennis murphy: the burned-out nissan maxima that carried the mother and daughter's bodies didn't yield any significant clues either.

the fire had destroyed everything but a tiny piece of jeans on delores's body and attached to the jeans, some leaves foliage experts identified as coming from a beech tree. odd, because there were no trees like that in the neighborhood. and the mystery only deepened when the autopsy results came back. ebony and delores were actually killed 24 hours prior to them being burned in the car. that was another hiccup in the case. where were these two bodies kept for a full day? dennis murphy: it seemed the dewitt's killer took immense risks to get rid of the bodies. you're talking about taking two women out of their house and transporting them to another location and then stealing a car, putting those dead bodies in the car, driving past the house that you just stole the car from, and then parking it in a driveway of a vacant house, then setting that car on fire and walking away.

dennis murphy: and the autopsy also revealed that delores and ebony were strangled, not shot, as the loftons had been. it was a puzzle. were they dealing with a serial killer or not? did you think one guy was responsible for both these crimes? i would go back and forth. one day i would-- it was all in that this is the same person. the next day, i thought it wasn't, because both crimes are so different. dennis murphy: then finally, the detectives caught a break. they learned that a month before the dewitt murders, the owner of the stolen nissan maxima had been the victim of a break in. she reported it but at the time, told police nothing had been taken. now she noticed her spare set of car keys was missing. so tony, as i understand, your detective's logic goes something like this. if i can find the person who broke in, who stole the key, who then used the vehicle to transport the bodies, i'm going to close to my killer. exactly. it certainly would give me a direction where maybe that person then can direct me to the killer. dennis murphy: 200 police officers blanketed the area

and brought in more than 80 people for questioning, all to no avail. for many prince george's county residents, like home invasion victims vicki and lloyd irvin, that meant only one thing, panic. it was crazy. i couldn't sleep at night. any sound, i had the-- i had alarms put up throughout the entire house, and plus we had the dogs. [barking] and bars on the window yes. the house was turned into fort knox, a barking, crazy dog who claws at the windows if he hears a doorbell ring. i mean, there was no peace in the house. and i was like, you have to turn some of this stuff down. i can't live like this because he's like, i don't care. this is going to save our life, you know. just the fear that spread was absolutely amazing. dennis murphy: by july 2009, four months after the dewitt murders and six months after the lofton murders, detectives were stumped. we kept calling them, and they wasn't giving us no answer. so that kind of pissed me off because i felt like we deserved to know something.

it was wide open. we had nothing. dennis murphy: you're out of your investigative playbook. anthony schartner: and then that's when it gets scary. dennis murphy: the detective had made a promise to patricia that he would take down her sister's killer. would that turn out now to be an empty promise? at this point, what he needed was luck, and luck was about to come his way from the most unexpected source. [gunshot] craig melvin: coming up, an unassuming neighbor comes forward with some unbelievable information. at that point, we realized that our investigation just took a drastic turn. craig melvin: when "dateline" continues. long after guests leave, viruses and bacteria linger. air fresheners add a scent. but only lysol air sanitizer helps erase the trace, eliminating odor and killing 99.9% of viruses and bacteria in the air. scent can't sanitize. lysol can. protect against rsv with arexvy. arexvy is a vaccine used to prevent lower

respiratory disease from rsv in people 60 years and older. arexvy does not protect everyone and is not for those with severe allergic reactions to its ingredients. those with weakened immune systems may have a lower response to the vaccine. the most common side effects are injection site pain, fatigue, muscle pain, headache and joint pain. arexvy is number one in rsv vaccine shots. rsv? make it arexvy.

the freestyle libre 3 plus sensor tracks your glucose in real time, and over time it can help lower your a1c. ♪♪ this is progress. learn more and try for free at freestylelibre.us ♪♪

hi, i'm richard lui with a news update. over 60 million americans are facing the threat of severe winter weather this morning. the mid-atlantic is expected to be most effective with dcm philadelphia bracing for icy conditions. ukrainian forces launching

a surprise offensive in the kursk region. the move was confirmed by moscow's defense ministry. it comes ahead of a push for a peace deal with the incoming trump administration. for now, back to dateline. two double murders in one maryland neighborhood sent the community into a full-blown panic. investigators had cleared the usual suspects. and that's where both cases seemed to stall. then detectives linked a nearby break in to one of the crimes. all roads to find that thief led them nowhere. but a big break was just around the bend. here again is dennis murphy with "the unusual suspect." dennis murphy: prince george's county detectives tony schartner and bernie nelson theorized the home burglar who stole a spare key to a nissan maxima might lead them to a serial killer.

but how to find him? we chased down all those leads, and it took us, you know, several weeks. and we came up with nothing. dennis murphy: then in july 2009, schartner got an unexpected tip. federal agents from the atf, the bureau of alcohol, tobacco, and firearms, had arrested two men for selling stolen weapons. [gunfire] they suspected one of them had also been involved in several burglaries in the area. his name was jason scott. jason scott lived two, three blocks away from the dewitt's house. so obviously that's somebody that i want to go talk to. dennis murphy: the detective and the thief met in a police station holding room. the subject, who was quick to deny he had anything to do with any of the burglaries, looked to schartner like a pipsqueak. he was a small guy. he was meek. his voice was very low. he wouldn't speak to me as you and i are speaking.

he would only whisper. he would actually come up and actually whisper in my ear. did you think, tony, at that point, i got a suspect here? no. dennis murphy: atf agents john cooney an dave cheplak led the federal investigation into the weapons theft. and they, too, were having a tough time trying to read jason scott. usually, we're pursuing the most violent criminals in the united states. and for lack of a better word, you know, this guy wasn't a thug. dennis murphy: in fact, jason turned out to be a college graduate and a valued employee at ups. we did a background check on him. and really, he had no criminal history. dennis murphy: jason and his accomplice were charged with weapons theft and possession. but given that neither had a criminal record, a judge released them, pending trial. she basically had to make a decision, all right, you're not a flight risk, and you're not a danger to the community. so both of them were released to home monitoring. so they could come and go. court is telling them, go and sin no more. don't be stupid. don't be a bad guy. agent: yes. but the atf agents weren't about to let jason scott,

walk away quite so easily. they suspected he had other co-conspirators in the weapons theft. and instinct suggested he just might be the kind of petty criminal happy to throw others under the bus in exchange for a lenient deal. so the feds offered him what's called a proffer session, sometimes called king for a day. in monopoly, it's known as a get-out-of-jail-free card. it's an agreement between the prosecutor and suspect that says, essentially, you tell us everything you know, and we'll go easy on you. and the stuff that i spill out, you will not come after me. that's the agreement? if we can't prove that any other way besides him telling us, then there's nothing you can do. you can't use his statements against him when-- when that statement is given in that proffer session. dennis murphy: agents cheplak and cooney had been on the job for a long time. but what happened next stunned even them. john cooney: so we come into the room to conduct the proffer session with jason scott. myself and dave cheplak are on this side of the table. jason and his defense attorney are sitting across from us.

we see that jason has three pieces of paper in front of him on the table. dave and i take a look at the papers and see about 40 different addresses. suddenly. jason admits to breaking into all these houses. and not only that, nine of the houses, he tells us he breaks into, wakes people up, points guns at their heads, and robs them of their valuables. at that point, we realize that we're not just dealing with a guy selling and stealing guns. our investigation just took a drastic turn. dennis murphy: jason had rocked the federal agents off their script. the king-for-a-day deal was about copping to the firearms charge. and here he was telling them instead that he and his accomplice, marcus hunter, made a living by pointing guns at so many people's heads, including during that botched home invasion of the irvin family. but he's cut his deal, john. you can't go after him on those burglaries, the home invasions. at that point, you're correct. he's home. he's off, scot free. home free, yeah. dennis murphy: even better for jason, he believed his accomplice, marcus hunter, alone would be left to take the fall for their crime spree.

he figures, if i'm the one who's willing to testify against marcus, you know, that'll be his opportunity to lessen his sentence. smarts, cunning, how good was this guy? he certainly had a plan, and he had an idea of what he was trying to get away with. it really was a real-life cat-and-mouse game for him. dennis murphy: back at the county, detective schartner was floored when he heard from a colleague that the pipsqueak he'd interviewed and dismissed the week before had fessed up to a majority of the unsolved home invasions and burglaries in those well-to-do neighborhoods of prince george's county, including one his colleague had been investigating. and i thought, oh, good for you, you got your case closed out, but i'm still here with four dead women that we haven't solved. i said, hey, just out of curiosity, can you give me that list? dennis murphy: when the detective plotted the addresses jason had pushed across the table onto a map, he couldn't believe the picture that emerged. is this an aha moment in your investigation?

this is the aha moment. this is our first break in the case. craig melvin: coming up-- we don't know if we have our guy, but we certainly have now something to investigate. craig melvin: the investigation was about to lead them here, something called "the spooky house," and a federal officer on this case would soon be spooked himself, when "dateline" continues. dry eyes still feel gritty, rough, or tired? with miebo, eyes can feel ♪ miebo ♪ ♪ ohh yeah ♪ miebo is the only prescription dry eye drop that forms a protective layer for the number one cause of dry eye: too much tear evaporation. for relief that's ♪ miebo ♪ ♪ ohh yeah ♪ remove contact lenses before using miebo. wait at least 30 minutes before putting them back in. eye redness and blurred vision may occur. ♪ miebo ♪ ♪ ohh yeah ♪ ask your eye doctor about prescription miebo.

♪ miebo ♪ this is ground zero. this is where i responded to was this location. and this is where the dewitts were found. dennis murphy: thinking he'd made the deal of a lifetime, mild, meek jason scott had confessed to a wave of home invasions and burglaries in prince george's county, maryland. but by doing so, he had unwittingly provided homicide investigators with the first real lead in the lofton and dewitt murder investigations. what happens up here as you continue to go up? what are the other dots? so these other various dots here along the map are the locations where jason scott admitted to breaking into the houses here on woodlawn. dennis murphy: and here's what the detective found strange. jason had admitted to every unsolved burglary on the block, all but one, the house from where the nissan spare keys were stolen. for me, the most important part of this puzzle was to find out who broke into this house right here. and in the interrogation, he did not give you that address. he did not. dennis murphy: an anomaly, schartner wondered?

or did jason know just how important the car keys were and deliberately keep that house off his list. we don't see guys that break into houses and steal a tv then morph into a serial killer. we don't know if we have our guy. but we certainly have now something to investigate. dennis murphy: detective schartner and nelson teamed up with atf agents cheplak and cooney to create a task force to solve the riddle of jason scott. when you guys talk to friends and family, trying to figure out who he was, did anybody tell you he was a nice guy, can't believe that you've got them in the frame for this? nobody had anything like that to say about him. as a matter of fact, most people knew nothing about him. he was almost a ghost. dennis murphy: a ghost, indeed. when investigators examined items seized at jason's home, they found this, disturbing videos he apparently shot as he snuck around the neighborhood. turns out jason scott was as scary a peeping tom as investigators had ever seen.

video of someone walking through the woods, videotaping people through their homes in various states of dress and undress, getting ready for work or getting ready to go to bed. this is deeply creepy stuff. absolutely. dennis murphy: the person who knew him best was marcus hunter, the accomplice first arrested with jason scott. but marcus wasn't talking. investigators wondered, was he afraid of jason? another former co-conspirator was telling investigators jason was no one to cross. agent: these guys would say, if i ever got into a fight with jason, jason, you know, wouldn't fight me back. but two weeks later, he-- he'd be the type of guy to come back and burn my house down. dennis murphy: three weeks after his king-for-a-day deal, jason scott was still walking the streets. and investigators knew enough about him to worry for their own safety. his mo was he would specifically go and cut the power to these homes. so one night, sleeping, and i kind of

become aware that all of a sudden, the power is off in my house. so knowing that jason knew my name and thinking that he could figure out where i lived, i actually grabbed my gun and proceeded to tactically clear my house just to make sure he wasn't the reason for the power being out. as i worked my way through the house and into the kitchen, i finally come up. and i notice that in the backyard, the entire neighborhood is dark. at that point in time, i kind of take a sigh relief. and i realize, it's not him. but that's how concerned i was. he's that dangerous of a guy, that i recognized he needed to be in jail. dennis murphy: if jason scott was smart, the task force simply had to be smarter. and investigators noticed jason didn't seem to understand an important legal nuance. his proffer didn't guarantee him complete immunity. the cops could not use his own words against him.

but they could use the words of others. so when investigators found that other accomplice of jason's, they grilled him. dennis murphy: these details eerily mirrored what happened in the dewitt murders. he likes to steal car keys, spare keys. and he likes to come back later and get that car. that was exactly the case with the nissan, right? first check. he liked to park cars in vacant houses, preferably houses that were for sale. again, the torched car with the bodies-- --was-- was a vacant house that was for sale. dennis murphy: detective nelson nailed down several connections between jason scott and the first mother-daughter murder, the loftons, most important of those, jason's car, a dark blue toyota camry. it matched the description of the mysterious car one of the lofton's neighbors had seen.

that could very well have been the vehicle that the neighbor had seen the night of the killing. yes. dennis murphy: then investigators discovered another sickening piece of evidence, a video jason made of the victims of one of his home invasions, a mother and her teenage daughter. brought her into her bedroom and set up a video camera. and in the process of setting up that video camera on which she was going to basically film himself sexually assaulting her, the camera just happened to pan right by his face. and that screenshot showed us this. wow. and this is what a lot of jason's victims saw. it's cold, calculating eyes, lifeless. dennis murphy: investigators were shocked, even more so when they dug up the old police report and noticed what the perpetrator they now knew to be jason had blurted out to the mother and daughter just before he left. ok, here it is. he said he didn't want to hurt us. but he said he was supposed to kill us.

dennis murphy: yet all this evidence was purely circumstantial, not enough to charge, let alone convict jason of murder. but that was about to change. and it had to do with the one case police had plenty of evidence for, the weapons theft. when the atf agents talked to jason about it, he mentioned "the spooky house," some kind of an abandoned old property off the beaten path in upper marlboro, the place where he said he and his accomplices used to go to divvy up the loot. detective schartner had a spooky feeling that they brought more than guns there. we're still trying to find the place or a house or wherever where the dewitts were stored or kept for those 20-some-odd hours. so this spooky house, whatever it is, could be the place. absolutely. dennis murphy: and according to jason's proffer, if his statements led to new evidence, that evidence could be used to prosecute him. my first thought and impressions were that this is going to be like an old, rickety house, maybe falling apart.

dennis murphy: it doesn't feel like we're heading to spooky house, guys. no. and it wasn't until we came here that we realized there was a long driveway here that maybe made sense. there it is, huh? the spooky house was a georgian mansion up for sale. and like the property where the nissan was set on fire, vacant. what a hideaway to do whatever you want to do away from prying eyes, huh? anthony schartner: absolutely. at night, this is absolutely pitch dark. this is just a playground that jason scott had. dennis murphy: the task force called in the forensic team. we walked down here through these rocks here. and that's when i first initially saw the sweater, which was actually right down here in the rocks. dennis murphy: it was the charred remains of a blue sweater, the kind ebony dewitt had worn the last time she'd been seen alive. and once we saw that, we said, all right, this is it.

this is finally something. and you're talking about a high-five moment. we looked a bit further-- walked down these rocks here. and then scattered within these leaves over here were-- were the jean pieces. dennis murphy: jeans that seemed to match the jean fragments recovered from dolores dewitt's body. leaves covered the ground there. and the task force wondered whether they were beech tree leaves, the type that were found attached to dolores's jeans. detective schartner brought an expert to the spooky house to identify the foliage. he pulled up here. and he said, this is the jackpot of beech trees. poor ebony and her mom were here, no question. without a doubt. dennis murphy: but to arrest jason, investigators needed more. in the meantime, they eliminated his accomplice as a murder suspect. so they hit him up again, hinting jason is talking, and if you don't, you'll be the one to take the fall. that did it. marcus hunter finally agreed to cooperate. right away, he dropped a bombshell about jason.

the specter of him becoming a monster grows with each and every stone that we overturn. craig melvin: coming up-- i think he truly thought he could outsmart us. craig melvin: could he? what would it take to put jason scott behind bars? when "dateline" continues. hon', take airborne! it has 7 key nutrients to help fill those holes your immune system may have. what holes? [screams] new airborne. 7 immune supporting nutrients. our most complete support yet.

protect against rsv with arexvy. arexvy is a vaccine used to prevent lower respiratory disease from rsv in people 60 years and older.

arexvy does not protect everyone and is not for those with severe allergic reactions to its ingredients. those with weakened immune systems may have a lower response to the vaccine. the most common side effects are injection site pain, fatigue, muscle pain, headache and joint pain. arexvy is number one in rsv vaccine shots. rsv? make it arexvy.

arexvy is number one in rsv vaccine shots. dennis murphy (voiceover): almost six weeks after jason scott walked out of the prosecutor's office

with a potential "stay out of jail" deal in hand, the task force persuaded jason's accomplice, marcus hunter, to cooperate. the king for a day was about to be dethroned. so, marcus tells us that about a month prior to the dewitts being killed that he and jason are running through the backyards because they had just done a job. and jason stops and looks into the dewitts' house, and he notices ebony and he starts to stare. and marcus gets uncomfortable and says, hey, we can't stay here all night. you need to go. dennis murphy (voiceover): much more damaging, the accomplice told the task force that after yet another robbery and approximately an hour before dolores and ebony were killed, he had given jason a ride to his car, parked just a block or so from the dewitts. and the accomplice had more. and he said that there was at one point-- and it was during the time that the loftons were murdered--

that he had seen jason scott for a short time frame with a glock 17. dennis murphy (voiceover): a glock 17, the very weapon used to murder karen and karissa. i had one of our investigators try to find out who purchased glock 17s over the last two years, and then contact those people and find out if they can account for their handgun. and he found out that a home was broken into 13 days before the loftons were killed. and during that break-in, their glock 17 handgun was stolen. dennis murphy (voiceover): and here is where detective nelson got lucky. the state of maryland requires handguns to be test fired before they're sold so it can archive each gun's shell casings to help identify or trace the weapon should it be later used in a crime. [gunshot] bernie nelson: we immediately took out shell casings and had them compared to that known shell casing from that known handgun.

and during that testing, they were able to verify that all six shell casings came from that one particular glock 17. that was the weapon that was used to kill both of my victims. once we found out where the murder weapon came from that was used to kill the loftons, we needed to find out if jason scott ever had that gun in his hands. so we asked his accomplice, marcus hunter, if they ever broke into a house in this one particular neighborhood. he said they did. it was only one house. we never told him which one it was, and he took us directly to it, the house that the glock was stolen from that killed the loftons. as far as that handgun goes, i think that was the nail in jason's coffin. we know that he stole that weapon. did that solve the lofton murders? it got as close as we were we were going to get. dennis murphy (voiceover): detective schartner and nelson arrested jason scott at his home on september 2, 2009. as i distinctly remember telling him,

jason, take a look at your house. this is the last time you'll see it. and he didn't even have a response. he just gave some type of noise, smacking his lips as if, i'll be back. i think he truly thought he could outsmart us. and fortunately, between bernie and i and the two agents from the atf, we outsmarted him. dennis murphy (voiceover): and personally, the takedown of jason scott made the detective a promise keeper. he said, i'm going to get him if it's the last thing i do. he said, i'm going to get him. and he got him. dennis murphy (voiceover): in exchange for his cooperation, marcus hunter got a reduced seven-year sentence for weapons possession. it would be another three years before the atf and county police analyzed all the evidence against jason scott. when all was said and done, he was sentenced to 85 years in prison. one of the things that the judge said-- and i'll never forget this-- is he said, you're not even a crime wave.

you're a tsunami of crime. satisfaction to take down a guy like this? extreme. it was the proudest moment of my career. dennis murphy (voiceover): but jason did cut one final deal. in exchange for acknowledging that prosecutors had enough evidence to convict him for the dewitt murders, the state agreed not to prosecute him for the loftons. that didn't sit well with the lofton family, but it was the best investigators thought they could do. the bottom line is, we know that jason is gone forever. he only has one life to give. we can't punish him any more than what he's already being punished. dennis murphy (voiceover): the serial killer, the master robber and burglar will likely die behind bars. the neighborhoods he terrorized are safe again. but under some roofs, there's been damage to that concept of home as a sanctuary. take vicki and lloyd irvin. they've kept their burglar bars, their home alarm system. they didn't know how much they needed that stuff until we filled them in. dennis murphy: let me tell you something

that'll probably freak you out. and this comes from guy number two in your house. he said after the home invasion, they came back. are you serious? he wanted another round. they parked in front of your place, did a little surveillance, scoped it out. and jason scott wanted to come back in and even the score. i didn't know that. that's scary. it could have been your picture on the 11 o'clock news. that's right. like, how does one person cause so much damage and so much hurt and so much loss for so many people? it still blows my mind. now that's all for this edition of "dateline." i'm craig melvin. thank you for watching. [music playing] hello, i'm andrea canning, atold me, he loved me."diane i told him, i loved him. he said, he'd be right back. i could hear a commotion of some sort,