Forensic Files

An unusual case involving the 1988 rape and murder of Nancy DePriest. After Chris Ochoa confessed, the case was closed. 8 years later, Achim Marino confessed to the same crime. DNA evidence cleared Ochoa while proving that Marino was the perpetrator.

The investigation into a brutal attack on two boys near a pond relies on evidence fished out of the murky water. It was the first case where Diatom evidence was used to place a suspect at the scene of the crime.

In 1988, the body of a young woman was discovered in an Ohio river. Most of the evidence had been washed away, but the victim's 6 year-old son unwittingly told investigators all they needed to know...without saying a word. The clue was in his genes.

In 1991, a high school girl vanishes after attending a party. The prime suspect had not one but two alibi witnesses for the night she disappeared. A solid alibi can often overcome much circumstantial evidence. But forensic evidence is another matter.

An examination of the first time animal DNA was used to solve a criminal case. When the body of Douglas Beamish's estranged wife Shirley Duguay was discovered, authorities linked 20 cat hairs found on her jacket to a cat owned by Beamish's parents.

1984 Rajneeshee bioterror attack: investigators uncover a plot to overthrow the government after a unique strain of salmonella makes people ill.

Two sets of scientists probe a woman's death.

The founder of American Atheists disappeared in 1995 along with one of her sons and granddaughter, along with $500,000 in gold coins. The police homed in on several suspects, including David R. Waters, who worked for American Atheists.

Two eyewitnesses may hold the key to the death of a motorcycle gang member.

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.

The investigation into the kidnapping and rape of an 18-year-old Ohio woman is aided when the victim returns hours after the incident occurred. With her help, the police are able to track the assailant Craig Bailey to his front door.

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.

How 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 evidence of foul play. But the coroner who performed the autopsy on the body found telltale clues.

A look back at the case of the River Park Rapist, who assaulted four women in South Bend, Ind., during 1996. Law enforcement officers arrested Richard Alexander, who was convicted in 1998 and sentenced to 70 years in prison.

The 1996 Seattle murder of suburban couple Raquel Rivera & Jay Johnson is detailed. Evidence from the couple's dog Chief eventually ties one of the murderers to the scene. This is one of the first cases where dog DNA was used to convict.

The story of firefighter Michelle Baker is related. After meeting Dr. Maynard Muntzing, she became pregnant by him. After this news, she was ill whenever they were together. The coincidences led her to suspect that he was doing her harm.

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.

The disappearance of Philadelphia college athlete Aimee Willard is investigated after her car was found 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 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.

Doctors cannot pinpoint the source of a businessman's illness.

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 that Evans Lee Curtis was the murderer.

The murders of an elderly couple leave police 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.

The murder of 9-year-old Jessica Knott is investigated. Investigators use a garbage bag to connect suspect James Edward Crow, Jr. to the crime.

An investigation into the murder of Katie Poirier is stymied by the lack of a body, but they find a few charred remains including a tooth. The tooth's filling contains unique properties that help investigators identify her remains. Further forensic evidence is then used to convict Donald Blom of her murder.

Forensic scientists work with the only clue recovered from a multiple-victim shooting: a 12-gauge shotgun. Scientists use unique methods to lift the serial number from the weapon in order to trace it to its owner.

The 3-year-old son of parents in Dripping Springs, Texas develops a respiratory condition. Then the father develops signs of Alzheimer's disease, and an investigator reveals that their ill health is due to a form of black mold in their modern home.

Sheila Bryan, who was convicted of killing her mother in a car fire, is granted a new trial. An expert fire witness's opinion on how the fire ignited differs from the prosecution's theory. If verified, it would clear Bryan of any culpability.

Authorities track a kidnapper who allowed his victim, 17-year-old Shari Smith, to write a last will and testament on a note pad, then informed the family of her murder, as well as the later murder of a 10-year-old Debra May Helmick. A phone number written on a previous page left a lasting impression, which helped to convict Larry Gene Bell.

Computers aid the police and FBI in solving a string of crimes in St. Louis.

Using an anonymous letter and geographical profiling, investigators close in on a serial rapist.

After a man's body is discovered a few miles from his home, police trace the crime back to his wife.

An examination of the 2002 DC area shooting spree that resulted in ten murders.