A young mother is found murdered near her Indiana home. Investigators have only one piece of evidence to help them find her killer. When a female body is discovered along the banks of an Alabama river, detectives must rely on a few tiny shreds of evidence to make their case. In New York, a woman is found dead at the bottom of a flight of stairs. Police must determine if her death is a suicide or murder. When there are no eyewitnesses to a murder, investigators look to the physical evidence to make their case. Forensic examiners seek out that one clue that can break a case wide open. A clue known as the silent witness. Named for the river flowing through its center, Elkhart, Indiana epitomizes the ideal of small-town America. It's a quiet, close-knit community. A place unfamiliar with the problems of violent crime. On March 3rd, 1992, a A father entered the Elkhart Police Department to file a missing person's report. My daughter Ruben Hernandez hadn't heard from his daughter in nearly 15 hours. 25-year-old Sandra Hernandez had dropped off her 3-year-old son around 5:00 p.m. the previous evening. Ruben believed that Sandra had a date that night. After saying her goodbyes, Sandra promised she would be back in a couple of hours to pick him up. Okay. Ruben and his wife were always happy to spend time with their only grandson, and they were glad to see that Sandra was starting to enjoy her life again. She had recently ended a turbulent 4-year relationship with her child's possessive father. Ruben explained that when he went to check on Sandra at her apartment, he got no response, though her car was still parked out front. Mr. Hernandez's concerns prompted Elkhart Police Lieutenant Tom Cutler to forego the 24-hour waiting period required before opening a missing person's investigation. He's a a fellow who is very concerned about not only his grandchild who he was taking care of, but also his missing daughter. He knew that she wouldn't take off and leave the child without touching base with him. After distributing Sandra's description to area law enforcement agencies, police quickly contacted her ex-boyfriend. Sean Parks strongly denied any knowledge of Sandra's disappearance. But he admitted that his 4-year relationship with her had been rocky. He said that recently he and Sandra had been arguing frequently and sometimes violently. Mostly they fought over custody of their son. Sandra vowed she would never give up her child. But despite the tensions, Parks insisted he would never hurt Sandra or their son. On the night Sandra disappeared, he claimed he was at work. Though Parks was cooperative, investigators know from experience that custody battles can sometimes end in murder. We checked with work and he was there all night and didn't leave the premise. So, we had no reason to believe that he had interacted with Sandra Hernandez on that night. With the only obvious suspect eliminated, investigators had to consider that Sandra might have left town on her own volition. And though that seemed unlikely, they had to be certain. They went to her residence to search for answers. What they found only supported their suspicions that the young mother had met with foul play. None of Sandra's clothes seemed to be missing and her luggage was still neatly stored in her closet. Hey Jim. In the kitchen, detectives found a container filled with $230 in cash. Sandra's driver's license was also in the tin with several other personal papers. Police saw no evidence to suggest that she had simply packed up and left town. I don't think she was going anywhere. Her neighbors later stated that they had not seen or heard Sandra at her apartment since she left to drop off her son the night she disappeared. With each passing hour, investigators realized that the chances of finding Sandra unharmed grew slimmer. They needed to determine if Sandra had in fact been on a date the night she disappeared, and if so, with whom? Sandra's friend, who worked with her at a door manufacturing company, came in to answer questions. She hadn't noticed anything unusual about Sandra's demeanor in recent days. In fact, the night she disappeared, Sandra was excited about a date she was going on with a co-worker. The man, Ricky Joiner, was a delivery driver at the company. And had been friends with Sandra for some time. When contacted by police, Joiner volunteered to come answer questions. Investigators immediately noticed fresh scratches on his face and hands. Joiner claimed a door falling on him at work caused the injuries. He admitted that he had been out with Sandra the night she disappeared, but only as friends. He said he picked her up at 6:00 p.m. They had dinner and then went to a movie that lasted about 2 hours. Are you ready to drive? Do I lie? He dropped her off around 9:30. Yeah, seriously. Sandra was in a hurry to pick up her son. Hurry up. Seriously. He watched her get into her car and leave. I'm sorry. Make sure she's home in the morning. I am. Make sure you get home safe. He hadn't seen or heard from Sandra since. Thank you. All right. I'll pray for you. Investigators asked Joiner to fill out a scientific content analysis form, referred to as a SCAN questionnaire. Like a polygraph, the questionnaire allows investigators to analyze a person's written responses for signs of deception or inconsistencies. The SCAN questionnaire is a written form that we give people that ask people pointed questions and ask them to respond in their own writing. So, it gives us a way to do a informal interview that sometimes reveals a lot about the information that the person's given. Investigators analyzed Joiner's statements. Using the information to reconstruct Sandra's movements prior to her disappearance, Lieutenant Cutler quickly found a troubling inconsistency. Part of his statement was that he had let her off at the apartment and she got into her car and left. Well, her car was still there, and the neighbors said, "No, she didn't Nobody came there that night." So, that leads us to believe that that part of the story was not true. Though police had no motive and no direct evidence that a crime had been committed, they obtained a warrant to search Joiner's residence. But, the search turned up nothing. Okay. Investigators knew they needed to look past the obvious. They collected ordinary household items, including trash bags from Joiner's kitchen, dotted with stains that appeared to be blood. Tests later showed, however, that the substance was not of human origin. Having found no hard evidence linking Joiner to Sandra's disappearance, the investigation threatened to go cold. canvasses of where she lived. Well, certainly they're looking grim. Unfortunately, we still don't know how to assess them. We suspected that some foul play has happened. Uh we've seen cases where people take off and vanish for reasons that nobody knows about, and they come back. Uh we were certainly certainly concerned that this was not a good situation, that we were going to find her dead. On April 15th, 1992, a month and a half after Sandra Hernandez was reported missing, their worst fears were confirmed. A farmer in nearby LaGrange County, Indiana, made a gruesome discovery. The body of a young woman. 10-4, describe the location. Okay, Claire, we're just a couple minutes away. As investigators in Elkhart, Indiana, continued searching for 25-year-old Sandra Hernandez, they received a call from police in nearby LaGrange County. A body matching Sandra's description had been found in an isolated field. A black trash bag covering the victim's head was removed and preserved as evidence. Using photographs, investigators confirmed that Sandra Hernandez had finally been found. Police began scouring the scene for any useful evidence. But nothing that could help them identify a suspect was found. After an exhaustive search of the area, it appeared that Sandra's killer had been careful not to leave any trace of evidence behind. At autopsy, the medical examiner determined that Sandra had died of asphyxiation resulting from manual strangulation. An analysis of the victim's stomach contents indicated that she had been murdered within an hour after eating. The medical examiner's analysis made Ricky Joiner's alibi impossible. Sandra could not have gone to a 2-hour movie after eating dinner with Joiner as he had previously claimed. But to prove murder, investigators knew they needed more than a few inconsistencies in Joiner's story. They had to come up with hard evidence to tie Joiner to the crime scene. But all they had was the trash bag recovered from Joiner's apartment. The trash bag turns out to have the most significance of anything that's taken. The trash bag that's found on the corpse uh when the state police tech decide to look at the evidence, send it to the lab, they talk to our techs, and they decide, "Hey, we've got this bag from from Joiner, the suspect's apartment. Let's send it to the lab with the bag we found on the corpse just to have them look at it." The bags were sent to forensic examiner John Vanderkolk at the Indiana State Police Crime Lab. Though it seemed like a long shot, Vanderkolk was asked to determine if the bag recovered from the victim and the bag seized from Joiner's apartment could have come from the same piece of plastic. To begin his analysis, Vanderkolk began by looking for repeatable class characteristics. The repeatable class characteristics would be the cutting tool that would use to cut the bags apart, the size and shape of the bag, the general color of the bag, the dimensions of the bag, and any um feature of the bag that can be repeated by the manufacturing process. By shining a light through the evidence, Vanderkolk determined that random color variations, microscopic impurities, and stretch marks were consistent between the bags. He continued his analysis by comparing the bags end to end. Vanderkolk found that the unique tool marks made as the bags were separated during manufacturing corresponded between the top of one of the bags and the bottom of the other. He was certain that the two bags had originated from the same piece of plastic, and in fact, they had come from same roll. I was convinced by the random pigment variation that carried over from one bag to the other. And also the random impurities and the stretch marks generated off the impurities that carried over from one bag to the other directly across the cut separation. The randomness definitely carried over throughout the circumference of the bottom of the bag from Sandra Hernandez's head and the top of the bag that Elkhart Police Department had recovered from Ricky Joyner's house. Ricky, Ricky Joyner, step out With no way to explain how a trash bag from his apartment ended up around the victim's head, Ricky Joyner was arrested and charged with the murder of Sandra Hernandez. Police surmised that after going out to dinner together, Sandra went with Joyner to his residence. But something went wrong. After a violent struggle, Joyner strangled Sandra to death. Police theorized that before putting her body into his car, he covered Sandra's head with a trash bag to keep traces of blood from being left behind. He then drove his victim to nearby LaGrange County. He placed her in the isolated field and left her there. After extensive legal proceedings, a jury found Ricky Joyner guilty of the murder of Sandra Hernandez. He was sentenced to 60 years in prison. Ricky Joyner believed that an ordinary trash bag would cover up his crime. Other killers will go to even greater lengths to conceal their guilt. Nestled in the Tennessee River Valley, the city of Decatur, Alabama, clings to a rich and colorful past. Its laid-back southern charm and its reputation as a fishing haven attract thousands of sportsmen each year. But in 1988, the river attracted a different kind of visitor. On July 5th, a fisherman called Decatur police after stumbling upon a body dressed in a nightgown and a blue pajama top near the shoreline. Police could determine that the body was female, but little else. The victim had been decapitated. After securing the area, investigators began the task of processing the scene for clues that could tell them who this victim was. They knew that because she had been decapitated, her identity would be the key to exposing this killer. The crime scene had little to offer. Blood-spattered rocks on the path and drag marks in the overgrowth led detectives to conclude that the victim had been killed elsewhere and then brought to the river. There were no signs of tire tracks or anything else that could help police identify the killer. With only the victim's fingerprints to work with, Sergeant John Boyd of the Decatur Police Department began trying to put a name to the Jane Doe. And from those fingerprints we tried a number of of agencies to see if we could make an identification. We we tried through here, we tried through Huntsville, and we couldn't get anything. To expand the search, the prints were cataloged and then forwarded to the FBI, whose national fingerprint database might yield better results. In the meantime, investigators hoped an autopsy could tell them more about how this victim died. Determining the exact cause of death would be difficult. But the medical examiner did find a few faint ligature marks below where the head had been severed, indicating that the victim had been strangled before being decapitated with a dull cutting tool. The pajama top and nightgown worn by the victim were collected and forwarded to the Alabama Department of Forensic Sciences. There, trace evidence examiner John Kilbourn began processing the clothes for any potential clues. We use a method that we call taping, where we take cellophane tape and using the sticky or adhesive surface of the tape, we press it down on the clothing and what this does is collect any particles, hairs, fibers, or other particles from the surface of that clothing. Kilbourn found a substantial number of hairs and assorted red and black synthetic fibers that had clung to the victim's clothing. Having more than 20 years experience analyzing similar evidence from crime scenes, Kilbourn believed he knew their origin. Some of the fibers were unusual in that the fibers had adhesive on them. Uh some type of glue on the surface. I have had other cases similar that had fibers similar to this. And uh in each of these cases it turned out to be uh adhesive from a felt car mat and a trunk mat. And I felt like in looking at these fibers were looking at possibly this victim having been in the trunk of a car. But until examiners had a source of comparison, the value of these items on their own would remain limited. Three days later, police believed they got their first break. Fishermen reported finding a human head floating near the shoreline. The area was less than a mile from where Jane Doe's body had been discovered. It had been decaying obviously at least 3 days. It was an overwhelming stench. The head was in a severe state of decomposition. We had extreme difficulty even picking it up to get it inside the boat. Uh we finally had to get enough uh plastic bags and and bag it up and uh put and put it on ice and about to put it in Styrofoam cooler and put it on ice and carried it down to forensic lab. But prolonged exposure to the elements made it impossible for examiners to find any identifiable features. Frustrated by the lack of progress, police realized that until they could find a way to identify the decapitated woman, this case would likely remain unsolved. Police in Decatur, Alabama were making little progress in identifying a headless female victim pulled from the banks of the Tennessee River. Over the next 10 days, investigators scoured through dozens of missing persons reports in an effort to learn the victim's identity. But none matched the description of their Jane Doe. The case threatened to go unsolved. But on July 15th, they got a break. Searching through military files, the FBI found a fingerprint match with the victim. I got a couple of questions. I can be over in just a Jane Doe was identified as 32-year-old Sandra Gail Leslie, formerly enlisted in the United States Air Force. Records indicated that she currently lived in Nashville, Tennessee, 120 miles away from where she was found. Police jumped on the lead. On that same day, after we learned who she was, we contacted Nashville Metro authorities and found out that they did in fact have a missing person report on Mrs. Leslie. Police learned that Sandra Leslie had been reported missing by her husband 2 days after her body was discovered in Alabama. Decatur police traveled to Tennessee and teamed up with Nashville authorities. Referring to this female friend, male friend. friend. Their first visit was to Sandra Leslie's husband. 39-year-old Billy Leslie told police that his marriage to Sandra had been shaky. But he loved his wife of almost 10 years and said they were trying to work out their problems. A few days before her disappearance, the couple dropped off their two kids with relatives in an effort to spend more time alone together. But on the afternoon of July 4th, Billy returned home from running errands to find that Sandra and her clothes were gone. Hello. Hey, how you doing? He said that in the weeks before her disappearance, Sandra had received numerous unexplained phone calls. Afterward, she would often leave the house with no explanation, leaving Billy to take care of the kids. He was convinced she was having an affair, though he didn't know with whom. As a matter of routine, police asked if they could look around. Billy gave his consent. To their surprise, investigators immediately found inconsistencies with his statements. Sergeant Robert Moore of the Nashville Police Department took part in the search. He said she took her clothes with her. Closet was so full of clothes you couldn't put another blouse in it. Uh there was no room for anything else. Dresser drawers, her clothes are gone, but yet every drawer was uh full. I mean, it it it just didn't look like somebody had moved out. Though Billy couldn't explain the discrepancy, he insisted that he would never hurt his wife, and he certainly had nothing to do with her murder. He agreed to let forensic technicians process his living room. Luminol was applied to the floor. But investigators found no traces of blood or any other signs of violence. But there were indications that the residence had been thoroughly cleaned recently. Can you bring the house light in? Despite the lack of evidence, investigators suspected that Billy Leslie was hiding something. Police began interviewing friends and neighbors. One neighbor claimed that Billy and Sandra fought often. Just a few days before Sandra disappeared, she heard what she described as a knockdown, drag-out fight coming from outside her window. When she looked outside, she saw Billy screaming at Sandra. As the fight escalated, Billy became physically abusive toward his wife. The neighbor didn't recall seeing Sandra after that night. She just assumed Sandra had finally decided to leave Billy. Perhaps that's exactly what Billy Leslie wanted everyone to believe. Come here have a One of Sandra's friends told police that Sandra had recently filed for divorce and as a result Billy had become increasingly violent toward her. I think first of all So much so that just before her death Sandra decided to change the beneficiary of her life insurance policy. We're working with the people in the Decatur, Alabama Prior to the change Billy Leslie stood to gain $150,000 from Sandra's death. She had feared for her life and she changed the beneficiary of that uh insurance policy uh to her brother in California. Uh and and and specifically asked him to make sure her uh children were taken care of should anything uh should anything happen to her. in the same area Billy wasn't informed that he was no longer the beneficiary. For investigators a possible motive for murder was beginning to emerge. Billy Leslie as far as he knew had a lot to gain from his wife's death. But so far their case was only circumstantial. Later that evening police obtained a warrant to search Billy's car possibly used to transport Sandra's body to Alabama. Luminol was applied to the trunk. Investigators found an overwhelming amount of substance that appeared to be blood. Billy Leslie explained he had gone fishing recently and put his catch into the trunk. The trunk mat was collected and sent back to the Decatur the lab for a more thorough forensic examination. While waiting for the test results, investigators continued to build their case. Hoping to find witnesses that could put Billy near the crime scene, police released details of the murder to the media in Alabama. A few days later, the tactic paid off. A Decatur resident remembered having a conversation with a man at a convenience store a few hours before Sandra's body was discovered. He had asked where to find a good fishing spot. The woman directed him to an area half a mile away. It was the same location where the victim was found. She was shown a photo lineup. She had no idea who the suspect on the photo lineup was, but she was able to immediately point to Billy Leslie and say, "This is the guy. This is the guy that was here and asked me about a place to fish." The witness testimony put Billy Leslie just a half a mile away from the crime scene on the day of the murder. And investigators had no doubt that he was responsible for his wife's death. Now, they hoped the crime lab would provide irrefutable proof. Authorities were closing in on Billy Leslie, the man they believed responsible for the decapitation of his wife, Sandra. Though their case was largely circumstantial, they hoped the trunk mat collected from the suspect's car could physically link him to the homicide. After serological tests determined that the blood found on the trunk mat was not fish blood as Billy Leslie claimed, Alabama Department of Forensic Sciences trace analyst John Kilbourn began analyzing dozens of hairs and fibers recovered from the mat. Using a comparison microscope, he began looking for common characteristics between samples from the trunk mat and those recovered from the clothes Sandra Leslie had been wearing. The color, texture, and cross-sectional shape of the fibers matched. We found a number of fibers from the victim's clothing that were consistent to the uh some of the known fibers from the trunk mat as well as some foreign fibers that were in the trunk mat. So, we were able to to show a link between the the fibers and the hairs out of the vehicle to the to the victim herself. Sandra Leslie's body had been in the trunk of that car. And the only other person known to have driven the vehicle was her husband, Billy. Billy Leslie was arrested and charged with the murder of his wife, Sandra. You neglected the kids. You neglected me. Police theorized that Billy Leslie believed he had much to gain from killing his wife before their divorce was finalized. That's exactly what I'm talking about. On July 4th, 1988, after a heated argument, Billy made the decision to kill his wife. After strangling Sandra, he loaded her into the trunk of their car and set out to dispose of the body on the banks of the Tennessee River in Decatur, Alabama. Not realizing that her fingerprints were on file with the military, Billy believed that separating the head from the body would make identification impossible. In December of 1989, Billy Wayne Leslie was convicted of first-degree murder and sentenced to life in prison. Even in death, Sandra Leslie managed to leave behind clues that pointed to her killer's identity. But in some cases, investigators have no idea where the evidence will lead them. The quiet middle-class neighborhood of Lake Grove, New York is a haven of suburban life. The community's illusion of serenity, however, was unable to provide protection from tragedy. On April 7th, 1994, police and paramedics were dispatched to the home of 47-year-old Stuart Kovacs. Kovacs said that Irene, his wife of more than 20 years, was inside, dead. He believed she had killed herself by jumping off the second-floor balcony. All right. Not wanting to contaminate the scene, the officer allowed only one paramedic into the house. Inside, 45-year-old Irene Kovacs' lifeless body was lying on the floor, covered with a towel. Her hair was wet, indicating she had recently showered. The paramedic noted bruising on the victim and a cut lip. An empty container of gasoline additive lay nearby. A large quantity of the substance was found pooled in the victim's mouth. It appeared that Irene Kovacs had poisoned herself and then jumped or fell from the second-floor balcony. Stewart Kovacs said that while working in the garage, he cut himself on a power tool. Going inside to get a Band-Aid, he discovered his wife on the floor. Panicked, he called 911 and then went upstairs to the bedroom to get a towel to cover her and to clean up his wound. On the couple's bed, he discovered a suicide note tucked underneath the family Bible. As a matter of routine protocol, homicide investigators were dispatched to the scene. Armed with a video camera, the team made their way into the residence. Almost immediately, they were struck by the victim's appearance. Lieutenant John Gearach of the Suffolk County Police Department explains. It's somewhat unusual that a woman would want herself to be discovered not dressed. Uh in and of itself, that is not proof of anything other than suicide, but it is one of the the circumstances that we take into account as we investigate. After removing the body, police continued examining the scene. On the second floor landing, they found a piece of recently dented sheetrock on the wall about ankle height, as though it had recently been kicked in anger, or perhaps a struggle. Unsure of its significance, the area, along with the rest of the scene, was thoroughly photographed. A short while later, after learning of his mother's death, the Kovacs 19-year-old son came in to speak with detectives. He said that the situation at home had grown tense in recent months. Just he he had probable cause to think so. He found a His parents' divorce was due to be finalized soon, and his dad had become increasingly abusive, often exploding into a rage over nothing. In one recent incident, Stewart Kovacs returned home early from work and confronted Irene with a note he found that had been sent to her by a business associate. Though Irene denied any wrongdoing, Stewart accused her of having an affair and began threatening her with violence. Suffolk County Homicide Detective Robert Doyle. The Kovacs children indicated to us that there was a very, very poor relationship at home. That apparently Irene Kovacs was in tremendous fear of Stu Kovacs. He abused her mentally, probably more so than physically. It was a uh It was a real hellish situation to be children in that particular home. The son added that on the night before his mother's death, she had seemed normal and happy, not at all depressed or suicidal. For investigators, the routine suicide investigation had raised more questions than answers. Irene Kovacs just didn't seem a likely candidate for suicide. Now, police realized that the circumstances surrounding this tragedy demanded a closer look. Though it appeared that 45-year-old Irene Kovacs had poisoned herself and then jumped off the second-floor balcony of her home, police in Lake Grove, New York were not convinced. A few hours after her body was discovered, police returned to the residence with a warrant. Now, they were searching for evidence that Irene's husband, Stewart Kovacs, had murdered her. Forensic examiner Robert Genna was asked to assist in the search. Fact that we have somebody claiming that this is a suicide, the husband, and the pieces of the puzzle just don't seem to fit a suicide, uh you now have to focus strongly on the physical evidence to try to either show that it was in fact a suicide or show that it was in fact something other than a suicide. To disprove the suicide story, police searched for evidence of a violent struggle. And though Kovacs blamed a deep cut to his finger on a power tool accident, police speculated it could also be explained by a blow to a sharp object like a tooth. But traces of Stuart Kovacs' blood were found exactly where he insisted the accident took place. The search continued inside the home. In the couple's second-floor bathroom, police found traces of blood on the commode lid. A washcloth found in the sink also appeared to be blood stained. Kovacs said the blood had come from his injured finger. Investigators collected the evidence. In the bedroom, an officer recovered the suicide note found earlier by Stuart Kovacs. Even though the writing was identified as Irene's, a close inspection of the language caught investigators' attention. What he purported to be a suicide note was in fact some writings of Irene Kovacs. It really had nothing to do with suicide at all. She was talking about her life. She was talking about various things that she was going through personally in her life. At no point did that particular note indicate or suggest that she was going to commit suicide. Unsure what to make of the evidence, police hoped Irene herself could give them answers. The medical examiner determined the cause of death was blunt force trauma to Irene's head and chest. But he could not rule out that the injuries occurred as a result of the fall from the second floor. Blood and tissue samples were collected and forwarded to the Suffolk County Crime Lab. There, toxicologists began analyzing the samples for the presence of the alcohol methanol, the main compound used in gasoline additives like the one Irene allegedly swallowed. First, examiners analyzed Irene's blood samples by using a gas chromatograph. An apparatus that separates complex mixtures into individual compounds. The analysis of the blood confirmed that fatal amounts of methanol were present. Toxicologist Ed Bricklayer of the Suffolk County Crime Lab continued the analysis on the tissue samples. Subsequent to that finding, we analyzed other specimens that were received. Uh primarily gastric contents, intestinal contents, and esophageal contents. Uh those specimens revealed no methanol to be present, which was totally contrary to the notion that Mrs. Kovacs could have consumed uh methanol shortly before her death. Uh the reason this is the case is that it takes a period of time, anywhere from a minimum of approximately 1 hour upwards to approximately 4 to 5 hours for the alcohol to be removed from the stomach. For methanol to be found in the blood, but not in the tissues, told examiners that the gas additive had been absorbed through Irene's skin, not ingested through her mouth. She never swallowed the gas additive. To make sense of the findings, police turned back to forensic examiner Robert Gena. Using photographs and diagrams from the scene, Gena found a clue. There were portions of Irene's body lying underneath the second floor landing. It was unlikely that she came to rest in that position after falling over the railing. And Stuart Kovacs claimed he never touched Irene's body. And there was something else. One of the photographs revealed that the gas additive stains on the floor formed an outline of Irene's body. In order to get this type of pattern, the victim would have to have been lying down in this position when the material was deposited on her, as opposed to her falling from the top landing already having the material in her system. So, it was consistent with her being in this position, lying on her back, the liquid deposited on her face and body, causing this outline that led us to believe that this particular case was not a suicide, but a homicide. The outline Coupled with the toxicologist's findings, the evidence showed that the gas additive had been poured into Irene's mouth while she was already dead or dying on the floor. To make their case, police still needed proof of a struggle. Examiners performed DNA tests on the various blood samples collected from the couple's bathroom. Believed to have been left by Stuart's cut finger. But the analysis disproved Stuart Kovacs' story. All of the blood found in the bathroom had come from Irene. That proved that she had been bleeding prior to the fall from the balcony. For investigators, it was proof that Irene Kovacs had not taken her own life, but that Stewart Kovacs had taken it from her. With a warrant in hand, police quickly tracked down Stewart Kovacs as he returned home from work. He was taken into custody and booked for murder. Investigators believed that after beating Irene as she got out of the shower, Stewart Kovacs forced her over the balcony. After pouring the gas additive into her mouth to make her death look like a suicide, he smeared blood from a cut sustained during the assault on the power tool in the garage. On December 17th, 1996, Stewart Kovacs was found guilty of second-degree murder. He was sentenced to 20 years to life in prison. Some killers will stop at nothing to conceal their crimes. These are the When there are no human observers to a murder, investigators must look for a different kind of witness to reveal a killer's identity. They turn to the crime lab, where forensic examiners can uncover the truth by turning the smallest clue into a silent witness.