A mother is suspected in the murders of two of her daughters, when her third daughter finally convinces police to reopen two cold cases.

In the 1980s, a serial killer prowled the posh streets of Orange County. Police were unaware of the serial attacks until 1996, when DNA revealed the killer's secret and they linked four murders to a single DNA profile. Detectives uncovered three more crimes attributed to the man dubbed "The Original Night Stalker" before learning he had an earlier career as a serial rapist! Watch as cold case detectives compare the attacker's DNA with nearly every convicted violent offender in California.

The murder of an Ohio woman in 1974 is solved more than 20 years later after police get a crucial clue--the woman's husband was seen building a coffin-shaped box about the time the woman disappeared.

After the murder of her aunt goes cold, a woman helps launch Citizens Against Homicide, an advocate group that brings awareness to cases that have gone unsolved. And police solve a young girl's rape and murder when the car where her body was discovered acts like a refrigerator, preserving half of her body and allowing authorities to recover incriminating DNA from semen in her body.

A 13-year-old girl's mother is murdered and 20 years later she helps bring the killer to justice; and a dogged policeman gets to the bottom of the brutal murder of a 63-year-old newspaper delivery woman.

A woman's fall from a cliff in the Grand Canyon leads police to uncover a series of grisly murders, and investigators smoke out a killer when they find crucial DNA evidence on his cigarette butts.

A series of brutal rapes in St. Louis goes unsolved for many years until a fluke audit of a license plate number leads police to the culprit.

A boy's toy Batmobile car provides an important clue for detectives struggling to make a case against a serial killer who stalks and kills waitresses.

Fire investigator Jack Malooly helps crack the case of an arsonist and killer who set a series of fires to collect insurance money; and a prison inmate tells a homicide detective that he can't help him with his current murder investigation, but knows plenty about another murder that took place in California 15 years earlier.

Police run down more than 11,000 leads before coming up with a suspect in the murders of three Virginia girls; and the abduction and strangulation of a California woman continues to baffle investigators more than 11 years after the crime.

A killer's bite marks and a jailhouse snitch lead to a murder conviction in a case gone cold for eight years, and Bill Kurtis joins a group of super sleuths trying to solve the slaying of 18-year-old Jamie Weiss, found dead in her bathtub in 1996.

The suspicious death of 2-year-old Billy Blankenship is solved when police force his babysitter to re-enact the circumstances of his death. Then, a murder case is solved when the dead man's body is accidentally found by divers searching underwater for an antique car.

Klan leader Sam Bowers goes on trial for ordering the murder of an African-American storeowner 32 years prior, and investigators reopen the unsolved case of an African-American truck driver who was forced to leap to his death from a bridge by Klan members.

Investigators in Virginia, probing the murder case of a sailor, seek the help of a forensic anthropologist from the "body farm" in the Great Smoky Mountains. Dr. William Bass became an expert on the human body's rate of decay by watching bodies rot at his plot at the University of Tennessee and keeping tables of weather data.

A killer helps convict himself when he boasts about his crime to prison cellmates; and New Hampshire investigators probing the murder of a pregnant woman found raped, strangled, and dumped into her bathtub, get a new lead when they discover a similar case in Florida.

After a long manhunt, cops finally close in on a serial killer with the help of the Internet and information supplied by a subsidiary of Microsoft. And a drug trafficker jumps bail, goes into the bike shop business, and helps pioneer the sport of mountain biking while he's on the lam.

New DNA technology and the national DNA databank help police hunt down a rapist-killer 11 years after he committed his crimes, and a detective's painstaking recreation of a woman's shooting death proves it wasn't an accident.

A murderer's saliva, found on envelopes that he sealed, helps seal his doom 37 years after his first killing. And Colorado police crack a cold case 24 years later when they take a DNA sample from the victim's son that proves that his father murdered his mother.

A New Orleans police officer goes undercover on a Baton Rouge riverboat to gain a confession from one of the ship's maintenance workers who is suspected of murder. And a Wisconsin man, suspected of committing murder using a nunchukus, a weapon consisting of handles connected by a chain, goes on trial nearly 10 years after the victim's body was found on Christmas Eve 1987.

Police solve an old murder case with a painstaking examination of the tool mark on the plastic flex cuff that bound the victim's hands, and a 15-year-old murder case is finally cracked open when a disgruntled wife tells police that her husband committed the crime.

A quarter of a century after the murders of two nurses, Canadian police suspect that a former Toronto cop committed the crimes. A blow to the head of a garbage collector in San Jose leaves strange markings, and decades later a detective, with help from forensic science, matches the markings to the etchings of a vintage bar sign. California police hope that DNA will help them track down the man who stabbed and killed a woman as she sat in her parked car in front of a supermarket in 1985.

A thumbprint connects two separate murders and it is later discovered that the suspect had a strange fetish for women's lingerie. Then, an elderly woman is found murdered in her bed and the only evidence is a single strand of hair.

It takes nine years and the work of cutting-edge forensic toxicologists to solve the murder of a medical examiner's wife. Then, a determined Alabama sheriff reopens the case of the deaths of two babies, hoping to get their mother to confess.

Police doggedly reopen a rape-murder case 25 years after the crime and find enough DNA evidence on the suspect's cigarette butts to bring him to justice. And a confession made to a "Baywatch" TV star helps police solve the three-year-old riddle of a wealthy Newport Beach woman's murder.

A police investigator discovers a letter written 16 years earlier that provides clues to a woman's murder. And a firearms expert supplies the evidence that South Carolina authorities need to put a man on trial in 2002 for a murder committed in 1961. It was the oldest murder case ever tried in the state.