Exploring how an American hit single from 1966 -- the cheater by Bob Kuban And The In-man -- foreshadowed the demise of the group's lead singer, Walter Scott (Walter Notheis Jr.), who disappeared in 1983.

In Texas 1988, Nancy DePriest was raped and murdered while working at Pizza Hut. After a suspect confessed and implicated another, they were both imprisoned; the case was considered closed. Eight years later, another man claims that he committed the crime, and investigators must use forensic evidence to determine the true killer.

Although a group of teenage thugs are suspected of attacking two boys on a fishing trip, there is no solid evidence until a murky fishing hole provides some answers.

In 1988, when a young prostitute's body turns up in an Ohio waterway under ice, authorities have one tiny clue which could point to her killer, but face huge challenges due to her policemen clients and DNA evidence being washed away.

In a small South Carolina town in 1991, 17-year-old Crystal Faye Todd, a popular high school student, is raped, murdered and dumped in a deserted field, after attending a party. With few leads, authorities test the DNA of several friends and one match shocks everyone.

In 1997, two years after a series of unsolved kidnappings and sexual assaults in California. One of the victims suddenly recalled an important detail of the crime which she had not told police. She left some forensic evidence in the assailant's vehicle, evidence that left quite an impression.

In 1994, on Canada's Prince Edward Island, the body of Douglas Beamish's estranged wife, Shirley Duguay, was discovered. In a groundbreaking case using animal dna, investigators use forensic testing on a cat to help them solve the case.

A look into the 1984 Oregon food poisonings, we're detectives track down the outbreak to a cult which aims to use germ warfare to take down the government. [also marked as S7:E16]

A woman is found dead from a gunshot wound and police suspect her husband; however, forensic teams prove what really happened and the truth is stranger than fiction. [also marked as S7:E17]

In 1995, Madalyn Murray O'Hair, the founder of American Atheists, disappears along with one of her sons, her granddaughter, and $500,000 in gold coins. The discovery of a mutilated body helps police catch the culprit.

In January 2001, in Duluth, MN, two people witness a truck driving over an unconscious man twice, and they flee into a nearby bar. When the police turn up, the truck, the victim and the witnesses are gone. The eyewitnesses may hold the key to the death of motorcycle gang member, Erik Schrieffer.

In Pennsylvania 1984, a passer-by finds the torso of a woman in a cardboard box. Investigators rely on insect activity analysis by a forensic entomologist to determine when the murder victim was killed. She remained unknown until a year later, when her sister called to report her missing. Eventually she was identified and a man was convicted of her murder, but would further forensic entomology change the outcome?

An 18-year-old Ohio woman, who is abducted and then released soon afterwards, uses her knowledge of forensics to lead police to the kidnapper.

The police investigate when a severed leg is discovered in the garbage. Conventional means of identifying the victim are impossible, leading investigators to rely on DNA, forensic anthropology and toxicology to identify the victim. The victim was identified as Norman Klaas and, through forensic investigation of his home, investigators follow the trail of evidence to his killer.

How Illinois scientists solved a 1992 murder case involving cremation. It takes a long time and a very hot fire to cremate a human body, and thus destroy all evidence of foul play, but the coroner who performed the autopsy on the badly burned body of Charles "Jack" Lynch found telltale clues. Not only had the victim been burned, he’d also been stabbed -- 24 times, with two different knives. Police knew that a person, acting alone, would probably use only one weapon. So investigators were on the lookout for a couple of killers.

A look back at the case of the River Park Rapist, who sexually assaulted four women in South Bend, IN, during 1996. Law enforcement officers arrested Richard Alexander, who was convicted in 1998 and sentenced to 70 years in prison. In 2001, Michael Murphy confessed to one of the two rapes of which Alexander had been convicted and forensic developments reveal new facts about the case.

The 1996 Seattle murder of suburban couple Raquel Rivera and Jay Johnson is detailed. Investigators first believe the slayings were the result of a drug deal gone bad. However, no drugs are found in the house and the victims' blood isn't present on the clothing of the suspects. Evidence from the couple's dog Chief, who was also killed, eventually ties one of the murderers to the scene. This is one of the first cases where dog DNA was used to convict.

Firefighter Michelle Baker became pregnant by her lover, Dr. Maynard Muntzing. After this news, she was ill whenever they were together. The coincidences led her to suspect that he was doing her harm, so she set out to prove it.

A look back at a trio of unsolved murders that occurred in Wichita Falls, Texas during the 1980s, details how a fourth murder from the same time period provided the police with more than they realized. John Little, an investigator for the DA's office, picked up the cold cases years later and made a connection to the other murders.

The disappearance of Philadelphia college athlete Aimee Willard is investigated after her car was found, still running on the roadside. When her body is found, the police find unusual marks on her body and DNA evidence that eventually lead to her killer.

The investigation into the apparent overdose suicide of Reverend Bill Guthrie's wife Sharon. Detectives suspect foul play after they recover incriminating files from Bill's computer and learn of his infidelity.

The 1991 disappearance of Newport Beach, CA, resident Denise Huber stumps investigators. Three years later, Arizona residents call police to report John Famalaro, who has kept a Ryder rental truck in his driveway, which they suspect is stolen. Upon further investigation, police find a body within a freezer inside the truck, which they conclude is Denise Huber.

The 1987 disappearance of Houston resident Tracy Jo Shine is recalled. The investigation went cold until 2000, when a "cold case squad" learned that the woman's ex-boyfriend Michael Neal had bragged about killing her.

When a 62-year-old man opens a car restoration business and becomes seriously ill, his doctors cannot find the cause, but forensics can; identification of a highly toxic metal in the victim's blood leads to his poisoner.

The disappearance of 6-year-old Michelle Lee Dorr is detailed. Although her father confessed to murdering her, the police soon poked holes in his story, leaving the case unsolved for 14 years. New suspect Hadden Clark was heard talking to himself, which gave investigators a clue where Michelle was killed.

The 1996 investigation into 48-year-old Martha Hansen's murder in Anchorage is helped by a legal requirement that bars have video cameras installed on the premises. Using video, hair and blood evidence, investigators determine who her murderer was.

n 1994, friends reported that Jack Reeves' mail-order bride Emelita Villa had disappeared. The police centered their suspicions on Reeves and, while pursuing leads, uncovered information linking him to the deaths of two former wives.

The murders of an elderly couple, Edward Kowalzck and Gertrude Thompson, leave detectives stumped until, two years later, they receive a major break. A jeweler looking through old newspaper clippings recognizes a necklace the female victim wore as having been pawned in her own shop. [also marked as S7:E14]

The tragic murder of 9-year-old Jessica Knott is investigated; a garbage bag leads investigators to her killer. [also marked as S7:E34]

An investigation into the disappearance of Katie Poirier is stymied, but they find a few charred remains including a tooth. The unique properties of the filling in the tooth helps investigators identify her remains.