technology is going to bite people. >> this is my first homicidal arsenic poisoning and i hope it's my last. >> it's just you the have to look for truth and justice. >> you never give up the fight. car, a missing driver and no witnesses. >> it would seem she was still alive when she was removed from the car. >> who would do such a thing like this on a public roadway? >> was it an ambush or a random attack? >> this is my defensive little girl who had been shot at. >> it was a head scratcher from the get-go. >> some tiny evidence provides the answer. >> it was on her skin, on her jacket. you can't get rid of this stuff. ♪ in southern california, like elsewhere in the united states, virtually everyone celebrates independence day.

some celebrate a little too much. that's what police thought when they found a deserted car around 4:00 in the morning with the engine still running off route 118, just north of los angeles. >> a lot of people thought maybe somebody was drunk and they had abandoned their car alongside the road. >> but a closer look revealed something more serious. >> we had several bullets that had went through the windshield into the vehicle and two additional bullets that had went through the side of the vehicle. >> a woman's shoe was inside the car. another was outside. blood was on the steering wheel. the driver's seat and floorboard. police fanned out all over the area. there was no blood trail, no victim. >> it was highly unusual for us to have a violent crime scene like that where the victim was missing. >> the car was a rental and had

been leased that day to megan barroso, a 20-year-old college student who lived nearby. her purse was covered in blood. her cell phone was inside. it looked as if she had tried to use her phone to call for help. >> she had gone to a fourth of july party with her best friend and some other young people. i believe in the beach area. >> according to friends, megan left the party alone at 2:45 a.m, a little more than an hour before her car was found. police checked local hospitals, but no one matching megan's description had checked in. >> we didn't know if this person was either dead or alive at that point. there was a significant amount of blood in the car, not enough to suggest that the person was, in fact, dead. >> my daughter was out there somewhere, and i was hoping i would get a call from her, any day, any minute. no call came.

>> investigators found five shell casings at the end of the exit ramp and another about 200 feet away. >> our forensic people were able to tell us that it most likely was an ak-47 type rifle, an assault rifle. >> knowing megan had been assaulted with this ak-47, again, it just sends chills of agony through my mind. >> investigators also noticed a fresh scrape along the driver's side of the car. it looked as if megan's car had been sideswiped. then investigators got a huge break. they learned that megan's rental car was one of the first to be equipped with an event data recorder. >> the event data recorder is a huge step forward in traffic safety. it's like the black box in an aircraft that gives us an opportunity to better understand how crashes happen.

>> the recorder, a small onboard computer, is always on. in the event of a crash, it automatically saves the previous five seconds of information. when megan's car hit the median, it activated the data recorder. it revealed that five seconds earlier, megan's car was at a complete stop. >> i think he started shooting at her, she was probably ducking. but at some point she realized, i better get out of there. >> the recorder showed megan floored the accelerator. >> she went to 100% open throttle. she jammed that gas pedal to the floor and she tried to get out of there. >> blood inside the car showed megan was wounded and possibly still alive, but where was she? >> we knew we had a body somewhere, we just couldn't find her.

as police search for 20-year-old megan barroso, they tried to reconstruct her activities on night of her disappearance. her friends said she left a fourth of july party at 2:45 in the morning and was alone.

her abandoned car was found at the bottom of an exit ramp off a deserted stretch of highway about an hour later. >> we found that megan didn't have any boyfriend problems. she didn't have anyone that was upset with her. in fact, it was the opposite. everybody liked megan. >> someone had fired multiple shots into megan's car with what investigators believed was an ak-47 assault rifle. to recreate the shooting, analysts used lasers to determine where the shooter was standing. >> we used a laser beam because it's a nice, straight light beam that we can just project through a number of holes, and it makes a good display. it allows us to see where the bullet has passed through, what it's interacted with. >> the laser analysis showed the shooter stood 60 feet away from megan's car when he started

firing, and he closed the distance with each shot. one shot hit the hood. three hit the windshield. another hit the driver's side door. investigators concluded the shot fired through the passenger side door happened somewhere else. >> it came in from a completely different direction. it couldn't have been part of the same series of gunfires without a dramatic change in the position of the shooter. >> this gunshot, along with a sideswipe on megan's car, led analysts to conclude this altercation happened on the highway. with the laser information and event data recorder, investigators put together this animation of what they thought happened. it was clear, someone tried to force megan off the highway by sideswiping her car. then megan's attacker moved to the passenger side and fired into her back seat. as megan drove off the exit ramp, her attacker must have

sped in front of her, blocked her path, and started shooting. there were four shots. she floored the accelerator. a fifth shot went through the side door and hit megan. the blood evidence shows megan tried to reach for her cell phone, possibly to call police. her car hit the median. the assailant apparently dragged her into another vehicle and drove away. >> you have to assume that the person that carried out this crime was very, very bold. very much a risk-taker. >> there were questions about who would do such a thing like this on a public roadway, and 118 is a very public roadway. >> the blood inside the car meant megan was wounded but was probably still alive when she was abducted. >> at that point, i realized that my daughter was in horrible trouble, that this was not, you

know, not a good situation and this was a real big, bad thing that was happening. >> the sheriff's department, along with other law enforcement agencies offered a reward for information leading to an arrest. but three long weeks passed with no leads on megan's abduction. then a simi valley resident called police with some information. he said he found a homemade videotape in his roommate's trash showing sexual acts so horrifying, he knew it needed to be reported to police. >> lo and behold, here's this guy raping these women. >> the man said he had no doubt the rapist on the tape was his roommate, 30-year-old vincent sanchez, an electrician who worked in the local film industry.

the tape showed sanchez raping numerous women on camera. >> it was quite horrifying to actually see a woman being raped and sexually assaulted. >> when investigators asked sanchez's roommate whether anyone in the house owned an assault rifle, he said he did. >> i'm sitting on the bed and he tells me, well, yeah, the gun's right here, it's underneath the bed. and as soon as i looked at it, the hair on the back of my neck stood up. >> it was an ak-47. detectives also found something near the trash outside the house. >> i excused myself from the interview to take a phone call, and i walked outside the residence, and over by some trash cans, i saw a garment of clothing on the ground and walked up to it, and i saw that it was a green jacket. >> a green gap jacket with an orange lining. it was fairly distinctive.

and he saw what he believed to be a bullet hole in the side. >> it was the same color jacket megan barroso wore on the night she was abducted. was it possible megan was still alive? we needed 30 new hires for our call center.

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just days after investigators found megan

barroso's green jacket in the trash outside a simi valley home, a search team with a cadaver dog discovered some skeletal remains in a ravine ten miles from the abduction site. dental records confirmed it was megan barroso. >> i was devastated, you know. i mean, i'm thinking this is drowning me now. this is absolutely terrible. you know, it was like, the lights are out now, you know. it was bad. >> the medical examiner recovered bullet fragments and determined that megan died from a single gunshot wound to her abdomen. >> but there was not forensic evidence to conclusively say that she had been sexually assaulted. >> it looked as if megan was still alive when she was left in the ravine.

>> she was in a fetal position with one arm bent under her head, like in a sleeping position. that wouldn't be a position that a body would land in. >> then the medical examiner noticed something unusual. red glitter. >> what they call pixie dust in megan's hair and on her clothing. and it was red glitter, in essence. >> megan's green jacket was found outside the home of vincent sanchez, a part-time electrician who came to police attention when his roommate found a homemade videotape of sanchez sexually assaulting several women. when police studied the videotape in detail, they discovered the women were the victims of the simi valley rapist. 15 unsolved rapes police had been trying to solve for the past five years. >> the perpetrator would break

into the home of the victims, primarily in the evening. some of the victims were young teenage girls, 15, 16 years old, with parents sleeping in another room within the household. >> when questioned by police, sanchez admitted he was the simi valley rapist, but denied having anything to do with megan barroso's murder. >> very hesitant to answer, didn't want to talk anymore. said he didn't know her, didn't know what i was talking about. had nothing to do with that. >> investigators search sanchez's pickup truck for possible clues. it was clear the truck had been thoroughly washed and cleaned, but tape lifts of the upholstery found something very difficult to get rid of, tiny specks of red glitter. investigators also found red glitter in the green jacket found outside sanchez's home.

they even found one microscopic speck on the ak-47 rifle sanchez's roommate turned over to police. to find out if all this glitter was from the same source, investigators sent it to edwin jones, a forensic scientist with one of the largest collections of glitter in the world, with close to 1,000 specimens. >> i have an unusual hobby of collecting micro things, and i've been collecting glitter for many years before this case and i've been collecting glitter since this case. >> under a microscope, jones discovered that this red glitter was a hexagon shape, approximately 250 microns. >> it's red on one side and silver on the other. it was a very unique type of glitter that just this one company had made. >> jones discovered that this glitter was not a bestselling item.

only 10,000 bottles had ever been made. investigators learned that during the fourth of july party megan attended, the host threw red glitter on everyone, including megan. >> i said, do you still have the bottle? she says, "yes, i do." so, we then went and recovered the remaining portion of the glitter. >> scientists confirmed the glitter in megan barroso's hair came from megan's friend, and it was the same glitter found in sanchez's truck, on the ak-47 rifle, on megan's jacket found in sanchez's trash, and in megan's own car. it was the only piece of evidence that tied sanchez to everything. investigators also searched sanchez's truck for blood. >> when the tech put a luminol on the inside of the vehicle, it

lit up like a christmas tree. >> dna testing revealed blood on the passenger seat was megan's. >> there was a horizontal apparent blood stain right in the area where megan's wound was to her side, indicating that she had been sitting upright in the passenger seat of that truck at one point. so, she wasn't dead. she was sitting. >> forensic tests on the scrape mark on the side of megan's car matched the paint from sanchez's truck. investigators test fired the ak-47 and compared the bullets to fragments found with megan's body. >> we tied that rifle to the crime scene and to the body both with the fragments that were taken from the car, from the crime scene. certainly, that helped to tie the rifle in to mr. sanchez and mr. sanchez then to the crime scene. >> then police discovered that

sanchez's real target that night wasn't megan barroso at all, but someone else.

investigators learned that on the fourth of july, vincent sanchez had an argument with a former girlfriend and he was angry because she hadn't invited

him to her family picnic. >> we theorized he took that ak-47, he got in his truck, and he was probably out looking for his girlfriend. >> whether he planned to use the weapon on his girlfriend or her family is unclear, but along the way, investigators believe sanchez saw megan at an intersection, changed his mind, and decided to follow her instead. the evidence shows sanchez tried to get megan to pull over. he then fired into megan's backseat. again, megan refused to stop. sanchez pulled ahead of her, cut off her path, and started shooting. megan tried to get away. she was hit by the shots through

the car door. megan may have reached for her phone to call help, lost control, and hit the median barrier. sanchez then abducted megan and drove off. the whole time she shed the distinctive red glitter into his truck, onto his rifle, and on her jacket. medical experts believe megan was alive when sanchez left her in the canyon ravine. he left her there without her pants and probably took her jacket as a trophy. in october of 2001, sanchez pled guilty to being the simi valley rapist and was sentenced to life in prison. he also pled guilty to megan's murder. sanchez claimed he didn't sexually assault megan.

>> the defense in this case, their main objective was to save him from a death sentence. >> but given sanchez's past, jurors concluded he did sexually assault megan and sentenced him to death. no one doubts that sanchez would have claimed more victims, but a strange combination of evidence, ranging from laser ballistics, to analysis of a car's onboard computer, to something as seemingly insignificant as glitter, proved his guilt. >> it was just amazing what the criminalists were able to do and the experts were able to say, to put together a very vivid picture for the jury as to what happened out there. >> i would say the most compelling science was the blood, the blood found in

vincent's vehicle and also the pixie glitter. that was amazing that they could put those pieces of pixie glitter together and show that it had been located in all those different areas and it was consistent amongst each other. up next, a young aspiring singer disappears. >> a telltale sign of somebody who was running away from something. >> she had a history of running away. she had always come back. >> surveillance cameras tell at least part of the story. >> when i saw the video, i started feeling very confident that we were focusing on the right guy. >> all they had to do now was to find him. ♪ i wanna love someone who will stand by my side ♪