daniel lee corwin was execut by lethainjection. he was 40 years old. i didn't want something like daniel corwin to hurt either of my kids or any other kids like tha narrator: investigators are convinced that the sketch created by wendy gauntt and karen taylor, the one that finally alerted detectives to daniel corwin, saved an untold number of lives. ♪ hidalgo: daniel corwin picked the wrong woman to attack that day. he still would have kept killing. there's no doubt in my mind that that would have -- there would've been more people out there dead. taylor: wendy put a face on him. there was a lot of investigative work done on all these cases, but make no mistake, it was wendy who brought down daniel lee corwin. she connected the dots. it was her strength that put it all together. burrough: not a lot of people like that. she actually said to me, "i've had a great life,

and the way i look on this is, i've had a great life for 38 years and one bad day." ♪ ♪ narrator: up next -- a late-night walk in an upscale neighborhood results in murder. the victim suffered a horrible, agonizing, painful death. narrator: surprise evidence sends investigators in an unexpected direction. murder has no boundaries. we're going wherever we got to go. narrator: after weeks of investigation, the case comes down to a single phone number. the bottom line to this investigation is forensics. the cellphone forensics actually brought the whole focus 180 degrees. the forensics is the glue that sticks it all together. ♪

♪ narrator: after meeting online and living for a while in europe, fred and sherry engel married and moved his consulting business to myrtle beach, south carolina, in 2006. the couple, both in their early 50s, lived in a complex called carolina forest. carolina forest -- it was really a planned-unit development, but it stretches into what was just a bare tract, a wildlife tract, for many, many acres. narrator: tom and karen rickerson were the engels' next-door neighbors. we knew her first because she lived in myrtle beach before fred s able, with his job, to move there. they were very quiet, you know, like, you know, to themselves. very nice people. narrator: shortly before midnight on april 21, 2008,

sherry woke up and couldn't find fred. he wasn't in the house, but his car was still in the garage. she had worked herself up into a panic. she knocked on her next-door neighbors' door and very plainly said then, but in a panicked way, you know, "i can't find fred. i don't know where fred is." narrator: tom rickerson searched the engels' home and found no sign of fred in the house or surrounding area. but sherry noticed that the keys to the mailbox were not in the house. the mailboxes for this development -- it's a bank of mailboxes that's right at the edge of the community, and it's in a very wooded area. narrator: this bank of mailboxes was about two blocks from the engels' house. sherry engel and tom rickerson drove there. thomas: i get out the car, and in front of the mailbox, i see a pair of glasses. and when i get up close, i see blood on the pavement.

well, sherry comes up, and i said, "sherry, get back in the car," 'cause i'm thinking whoever did this is still there. narrator: police were called to the scene and immediately searched the area. cestare: and approximately 10 to 15 yards inside the wood line, they see what appears to be a body laying there. [ camera shutter clicking ] narrator: it was fred engel. he'd been strangled with a highly unusual murder weapon. we see what appears to be a bootlace or a shoelace tied around fred engel's neck, and it's tied from the back. narrator: there was also a bloody gash on the back of his head. detectives assumed that, while he was at the mailbox, fred had been knocked unconscious, dragged into the woods, and then strangled. this gave detectives one piece of vital information straight away. fred was well over 6 feet and weighed 250 pounds. dragging him into the woods would not have been easy.

cestare: this is not gonna be a skinny, little kid. you know, this is going to be an adult-size male. narrator: fred was still wearing his wedding ring and an expensive watch. his cellphone was in his pocket. it's quite apparent at that point, robbery is probably not gonna be the motive. narrator: the only motive appeared to be murder. but who would want to kill fred engel? no one had a clue. ♪

narrator: evidence at the scene of fred engel's murder appeared to indicate his killer was lying in wait, that he knew where fred would be and at what time. this was a particularly vicious crime. it was the type of crime that, in my opinion, happens because someone knows someone. narrator: when fred's wife, sherry, found out what happened, first responders nearly had another emergency on their hands.

thomas: she became very hysterical, disbelief. she passed out. they were able to revive her, but she wasn't the same. hawes: it was heartbreaking to watch someone process and go through that instant grief of understanding that their loved one, their husband, has passed. narrator: when she could finally communicate, sherry said she had no idea who would want to kill fred and freely gave permission for police to search her house. we're looking for anything that can help tell us what happened to mr. engel. does he have a beef with any of the neighbors in the area? has any business partners or business contracts gone bad? any threats against him? narrator: and it turned out that fred did have a confrontation shortly before his murder with a teenager who lived in the neighborhood. this young man was so troublesome and scared so many residents that he and his mother

had been kicked out of the development. hawes: this young man had committed some small fires, had been accused of, like, shooting an air rifle at passing cars, different things of that nature that had basically made him unwelcome on other people's property in the neighborhood. narrator: and he fit the bill as a potential suspect. he had a significant temper, was the size of a regular man, so we're not talking about dealing with a child. we're talking about a child in a man's body. narrator: even more telling, the killer used a shoelace -- a crime-of-opportunity weapon, the kind of weapon a person might resort to on impulse. seeing the shoelace around his neck, to me, immediately started gears spinning in my head. the first thing it told me was this most likely was something that happened in a hurry. narrator: perhaps fred had another altercation with this teenager, and it escalated into murder. the young man's police interrogation did little to knock down this theory. hawes: his personality was very confrontational. he did not want to be there.

he would not provide any direct answers. everything was evasive. narrator: he finally admitted to being in the neighborhood but said he'd gone to a nearby shopping center later that night. surveillance video from that shopping center showed he was there. and, most important, he was there during fred's estimated time of death, between 11:00 and midnight. so, that takes him out of the equation. narrator: investigators now had to consider another possibility. fred's job tended to make enemies. hawes: he would come and evaluate businesses, see what was working, what was not, and very frequently, whenever fred came in, people lost their jobs. a lot of people didn't like fred. he was kind of the hatchet man. narrator: this meant a huge pool of potential suspects, not only in america, but also overseas. if you jump into a pond, you're gonna make a splash, and fred had jumped into quite a few ponds through his business. narrator: as detectives began the painstaking search

for possible suspects, they hoped dna might provide a break. could analysts get dna from the very unusual murder weapon -- the shoelace used to strangle fred? hawes: the shoelace looked dingy and old, so i immediately got optimistic, hoping, "okay, great. hopefully, there's gonna be dna on this shoelace." narrator: but in a setback no one anticipated, no foreign dna was recovered. jurors believe that dna is everywhere, and it is. but it's very fickle, and it's very hard to get a lot of times. hawes: we're really looking for it, and not having it in this case -- it really hurt me. narrator: as police dug for leads, they had to deal with a community on edge. karen: a murderer was at loose. no child was playing outside after 5:00 when the sun went down. nobody was jogging any longer. hawes: we've already crossed that 48-hour threshold. the investigation reached a point where i had essentially ran out of leads.

narrator: but a few weeks into the investigation, detectives got a potential break in the case. sherry's friends and family said they saw something strange shortly after fred's murder, on the very day he was laid to rest. during the memorial services for fred, several family members and friends of sherry noticed her having conversations and interactions with someone they didn't know. it was a tall, redheaded stranger. narrator: and this behavior continued well after the funeral. she seemed to have a very friendly, very cordial, on the borderline of being flirtatious relationship with this man that none of them knew. narrator: who was this man, and was it possible he held the key to fred engel's murder? ♪

her uncle's unhappy. i'm sensing an underlying issue. it's t-mobile. it started when we tried to get him under a new plan. but they they unexpectedly unraveled their “price lock” guarantee. which has made him, a bit... unruly. you called yourself the “un-carrier”.

you sing about “price lock” on those commercials. “the price lock, the price lock...” so, if you could change the price, change the name! it's not a lock, i know a lock. so how can we undo the damage? we could all unsubscribe and switch to xfinity. their connection is unreal. and we could all un-experience this whole session. okay, that's uncalled for. narrator: even though fred engel had moved his business to the u.s., he still spent a lot of time on the road. he would fly to new york for business meetings.

he would go to china. he would fly all over. narrator: and when he was gone, sherry would often stay with her family in kentucky. fred accompanied her whenever he could. sherry's family in kentucky absolutely loved fred. they enjoyed every time he visited. they really appreciated him. narrator: but there was something about sherry's behavior that concerned her family in kentucky. she was increasingly seen in the company of a man her family had never met. and they seemed to be more than friends. in kentucky, she had been seen with this unknown redheaded man, redheaded stranger, several times over the course of her visits, and she had been visiting frequently back home. narrator: family members didn't know him. and after fred's murder, sherry seemed to be spending even more time with him. the scuttlebutt on the street in breckinridge, kentucky, is sherry is having an affair with some redheaded guy that's really big.

narrator: family members in kentucky contacted the local sheriff to express their concerns. that sheriff promptly called his counterparts in south carolina. both offices agreed to work together to find out what, if anything, was going on. i asked the sheriff in breckinridge county, "is there any way -- would you mind, please, going out and kind of doing the legwork there in kentucky and finding out who this person may be?" and he agreed to do that for me. narrator: detectives in kentucky were eventually able to identify the man seen with sherry engel as tim rogers, a divorced 40-year-old contractor with no criminal history. he was 6'4", 240 pounds -- almost the exact size as fred engel. i immediately realized i had a person that was physically capable of doing the things that the crime scene and the body showed me happened that night. narrator: tim rogers drove a red pickup truck,

which turned out to be potentially significant. the night of the murder, a woman in fred's neighborhood saw a red pickup driving around the mailboxes where fred was attacked. the truck, which she had never seen in the neighborhood, drove very slowly to the bank of mailboxes and parked nearby. she said she never saw the driver exit the vehicle. she doesn't recognize the vehicle because, obviously, she lives there. she's never seen it before. she believes it's a chevy s-10 pickup. narrator: this truck was the same model as tim rogers' truck. but when south carolina detectives went to interview tim, his truck was no longer red. hawes: so, he changed the color from maroon or red to basically primer gray, which was very suspicious in and of itself. narrator: meanwhile, detectives were questioning sherry engel. on the night of the murder, she allowed police to search her house. one item they searched was her cellphone. there appeared to be nothing unusual on this phone.

but a few days later, while going over sherry's physical phone records, analysts found something unexpected. she'd deleted a series of calls that happened in the days leading up to fred's murder. all of these calls were to a number in the 502 area code. the area code was a kentucky phone number. narrator: and analysts traced the number sherry had called to a disposable burner phone purchased by none other than tim rogers. a concentrated burst of these calls happened the night of fred's murder at a time when sherry told police she'd been asleep. her whole story now was suspect. not only was sherry lying to me, she was lying to me during the exact time period that we're investigating where a homicide occurred. definitely something is up. narrator: analysts now did a deep dive on sherry and tim's phone activity, and it revealed a murder conspiracy

in the works for months. sherry was brought in for questioning and denied any involvement in her husband's murder. but when confronted with the evidence from her phone, would sherry's story change? ♪

narrator: sherry engel's reaction to her husband's murder -- she was so shocked, she had to be treated by paramedics -- made her an unlikely murder suspect. but if she was having an affair with tim rogers, investigators and even her relatives weren't so sure. sherry's own family is saying, "this is closer than friends. these two have something going on." narrator: rumors of an affair

and a lot of suspiciously timed phone calls were hardly proof of murder, but detectives believed those calls might be able to tell the story of what happened the night fred was killed. investigators got the locations of all the cellphone towers in the area and then did what's called a tower dump. cestare: a tower dump shows you every phone number in and out of a particular tower and the times that it occurs, how long the call lasted, the phone number it connected with or called to or called from. narrator: forensic analysts were able to pinpoint almost exactly sherry and tim's locations as they called each other the night of fred's murder. so, they could put the signal down into the size of about a car, i would say about 6 feet by 10 feet. i could say that this person was accurately within that area. narrator: sherry and tim had five phone conversations around the time of fred's murder.

the tower dump showed that four of those calls were either made or received right next to the mailbox where fred was attacked. the last call was from a hotel about seven miles from the site of the murder. i immediately walk in with the staff, show them a picture, and they immediately recognize him, say, "yeah, that's timmy. timmy's been staying here off and on for several months." narrator: hotel staff said he drove a red chevy s-10 pickup, the same make and model a witness reported seeing on the night of fred's murder, and he checked out the day after fred engel's memorial service. sherry engel had been paying for timmy rogers' hotel room with her credit card. narrator: sherry and tim were both questioned in connection with fred engel's murder. richardson: timmy is denying any involvement in the crime, and he's denying any relationship with sherry. he essentially played dumb about every topic that i asked him about. how did...

narrator: sherry's story wasn't much different than tim's. she said that timmy was a very dear friend of hers, that they spent time together, but they strictly had a friendship, and that was it. narrator: now detectives confronted sherry with the evidence from her cellphone. this interview ended, but it apparently had quite an effect on sherry engel. later that day, she came back to the police station and told detectives it was time to come clean. detective: okay. okay. a rattled sherry now confessed to the affair with tim rogers.

listen... she told police tim wanted to kill fred and marry her, but she never thought he'd go through with it and was shocked when he did. tell me, what did -- prosecutors say the phone evidence created a remarkably clear picture of what happened and proved sherry was in on the murder plot from the start. at 9:43, tim called sherry from the mailboxes. this was him calling sherry, saying, "hey, i'm in position. i'm ready to go. send him down here as soon as you can." narrator: at 10:35, sherry called tim, saying the plan had been delayed. at 11:05, she called tim again. hawes: this is sherry telling timmy, "get ready. i have sent fred to the mailbox."

narrator: sherry asked fred to get something from the mailbox, knowing full well he was walking to his death. the evidence shows tim rogers hit fred in the head with some sort of object, knocking him unconscious. tim dragged fred into the woods, took one of his own shoelaces, strangled fred to death, and then made his way at 11:42, tim called sherry. that is him telling sherry, "the crime has been committed. i've done it. i'm heading back to the hotel." narrator: at 12:03, tim called sherry from the hotel. he tells her, "i'm back at the hotel. i'm cleaning up." narrator: and now, in a clear indication she was in on the plot, sherry deleted all her calls to tim before she informed neighbors that fred was missing. when they got those records, it was a definite "a-ha" moment. narrator: in october of 2010, tim rogers was convicted of first-degree murder

and sentenced to 35 years. in december, sherry went before a judge. she hoped her story of being an unwitting accomplice in her husband's murder would buy her some mercy, but the evidence exposed that story as a lie. richardson: the judge couldn't stand her. he gave her 30 years. narrator: as unlikely as it seemed, tim and sherry apparently thought they could pull off this crime. their main mistake? they had no idea their cellphones had been tracking every move they made and proved without a doubt they had conspired to kill fred engel. the cellular data definitely shifted the direction of the investigation straight at her. richardson: i've described it over and over again as a busted lamp or a busted vase. the forensics is the glue that sticks it all together. cestare: that's what turned the whole investigation around to focus at her, to focus at timmy.