The investigation of a discarded sleeping bag containing bloody sneakers and a purse leads police to the body of a young woman, Carrie Love. Evidence from the autopsy and the crime scene was carefully collected and analyzed, but it would be a mark found on the victim's body which would enable police to track the killer, Jesse Pratt.

On the last day of deer hunting season in 1992, a woman is killed while walking her dogs in the woods. The victim has no enemies and her husband has an alibi, so police assume it was a hunting accident... until a strange letter turns up, allegedly written by the woman before her death. Police begin to wonder if the woman may have been the target all along, and a forensic document examiner, a slingshot, and an unusual physics experiment answer their question.

In 1995, an Alaskan police officer found a woman's body while on routine patrol of a public park. The victim had been stabbed to death and, during the autopsy, the medical examiner preserved the portion of her rib cage which sustained the fatal wound. A knife thought to be the murder weapon turned up days later, two thousand miles away. Forensic scientists now had an opportunity which seldom occurs, to compare the microscopic marks on the presumed murder weapon with the marks on the victim's bone.

A woman disappears without a trace; even though foul play is suspected, the leads don't pan out and the trail turns cold. Twenty years would pass before police are able to link a clump of hair discovered in an isolated area with the missing woman. Members of "NecroSearch," a group of volunteer forensic scientists, searched a remote area of Colorado a meter at a time, found the victim's body, and gave authorities the evidence they needed to bring the killer to justice.

A talented television news anchor was shot to death outside her home; it appeared to be a crime of passion, perpetrated by an obsessed fan. A police dog tracked the scent of the killer through the adjacent woods and back to the crime scene. Could the murderer be one of the onlookers, watching the police conduct their investigation?

Investigators sifted through the ashes of a fire which had killed a 40-year-old woman, the estranged wife of a police officer. At first glance, the fire appeared to have been started by an unattended cigarette. But when forensic scientists looked closely, they discovered the cause was far more complicated.

For seven years, a trio of men robbed one bank after another. They always got away before the police arrived, and they left no evidence behind. But the way they stood and the clothes they wore told a story that could be read by forensic scientists.

A young woman suddenly becomes critically ill; her symptoms worsen over time, eventually leaving her unable to walk. Then a bone marrow test reveals the cause: arsenic. Investigators now had to determine if the poisoning was caused by groundwater contamination or something much more sinister.

Residents of Noel, Missouri were stunned to learn that their bank had been robbed and the recently divorced bank president, 51-year-old Dan Short, was missing. His body was later found floating in a lake, securely bound to a chair with duct tape. When the tape was carefully reassembled using a technique known as end match analysis, investigators discovered one piece was missing. It would be that piece, and tips from concerned citizens, which would solve the crime.

In 1976, a young couple decided to celebrate their first wedding anniversary with a camping trip to Mount Hood. During the trip, the husband was shot and killed, and his wife told two different versions of the events which led to his death. Forensic psychiatry finally enabled her to distinguish fact from fiction, and the evidence from ballistics tests allowed investigators to determine what really happened.

The body of 16-year-old Leanne Tiernan was discovered nine months after she disappeared. Forensic scientists found clues that painted a virtual portrait of her killer. They knew he had a dog, he worked for the postal service, and that he had red carpeting in his home. Now all they had to do was find him.

20-year-old Donna Hartman, a Navy officer's estranged wife, fell to her death from a cliff overlooking the Pacific Ocean while on vacation with friends Virginia and B.J. McGinniss. Initially, investigators thought it was a tragic accident. But after a forensic examination of photographs taken at the scene, police had a very different picture of what had happened. They soon exposed Virginia as a serial killer who murdered not only her previous husbands, children, and other relatives, but also her friends, all for collecting life insurance. Virginia and B.J. had drugged Donna during lunch that day, after which B.J. pushed Donna off the cliff and they staged it to look like an accident. Virginia was sentenced to life in prison, but B.J. died of natural causes while awaiting trial.

Haunted by the disappearance of her mother some twenty years earlier, a young woman undertook an investigation of her own. Her mother's diary was in the now cold case file; there, in her mother's own handwriting, she discovered a dark family secret, which might have been the reason her mother vanished.

California police had several suspects in the robbery and brutal murder of an elderly couple, Cliff and Alma Kirk. Unfortunately, the forensic evidence was inconclusive, and the crime went unsolved. Ten years later, a determined forensic scientist used material from a dentist's office to uncover ballistic evidence which had been overlooked. He not only solved the crime, but he also made scientific history.

After a street fight took the life of a national wrestling champion, police had to determine if he was killed in cold blood or in self-defense. A jury decided it was murder, and sentenced the accused to a minimum of twenty years in prison. Six years later, he was granted another trial; a forensic animator who testified on his behalf offered a different explanation for the most damning piece of evidence.

19-year-old Devon Guzman was found dead in her car; the scene had been staged to make the murder appear to be suicide. During their investigation, police discovered the victim was involved in a love quadrangle, giving several people a motive to kill her. The killer's identity would be revealed by a piece of evidence found in a suspect's trash.

43-year-old Melvin Snyder disappeared one year to the day after beginning an affair with his friend Ron Harshman's wife Teresa. They'd briefly eloped to Montana, but after three weeks they'd ended their affair and returned to their spouses. 15 years later, with the help of a metal detector, police found evidence which would prove what had happened and who was responsible.

The body of a young California co-ed was found under an isolated ramp off the Interstate, and San Diego Police had no idea who would want this girl dead. But their questions would be answered when they discovered a tiny, unique fiber on the victim's clothing, which led them straight to the most unlikely of killers.

In 1974, Janice Hartman, a go-go dancer recently divorced from John Smith, told her family she needed to get away for a while, and then she simply disappeared. Investigators were suspicious because she took neither her car nor her clothes. The next twenty years passed slowly, and the family began to think they might never know what happened, until they received a phone call from the sister of the next missing wife of John Smith.

Colorado hunter Bruce Dodson, who'd been shot three times and killed while on a hunting trip with his new wife Janice, was the victim of a well-planned crime, not an accidental shooting. Investigators found a .243 caliber bullet in his lung and a .308 caliber shell casing near his body and suspected they were looking for two murder weapons, and two killers. They also had two suspects, both of whom had also been camping in the area; a witness who'd reported the crime, and Jason Lee, Janice's first husband who'd left her for one of their daughter's friends. But analysis of the forensic evidence pointed them in a different direction, and they soon discovered that the entire thing was a plot by Janice to eliminate both her husbands, live off Bruce's life insurance, and get revenge on Jason for abandoning her. When she found out Jason was camping in the same forest, she made sure she and Bruce set up camp as close to Jason as possible without arousing suspicion. The morning of the murder, Janice waded through a nearby swamp to Jason's campsite to avoid being seen, wearing coveralls and rubber boots she'd secretly brought with her to keep her clothes clean. When Jason left his tent, Janice stole his hunting rifle and followed Bruce on his morning hunt until he was alone. She then killed him and disposed of the gun, positive she had been successful in framing Jason. However, her plan fell apart when she tracked mud from the swamp into Jason's tent. A forensic analysis of the mud was all it took to exonerate Jason and prove his ex-wife's guilt. Janice Dodson was sentenced to life without parole for the first-degree murder of Bruce Dodson and for attempting to frame Jason Lee.

In 1984, California firefighters had battled ten arson fires in three weeks. When cigarettes and a scrap of paper connected the southern California fires to several fires further north, the hunt was on for a dangerous pyromaniac. Investigators finally found a fingerprint, and it pointed to a most unlikely suspect.

In 2002, a small community in upstate New York was devastated when Patty Wlasiuk died when her truck went into a lake. Her husband Peter stated he narrowly escaped as the truck entered the water. Investigators initially thought alcohol was to blame, but blood tests proved the victim was not intoxicated. Burdock seed pods found in her hair and on her clothes would indicate that this was no accident. It was cold-blooded murder.

When a woman disappeared without a trace, there were two possible explanations: kidnapping or murder. Concern was heightened when police learned that two other women had vanished under similar circumstances. Careful investigation, the talents of a forensic artist, and DNA profiling enabled police to link the crimes to a single suspect – an immigrant known to prey upon vulnerable women.

Hikers near Anchorage, Alaska discovered a body wrapped in sheets, which were edged in orange stitching. Authorities hydrated the fingers and obtained a fingerprint, enabling them to identify the victim. Clinging to the sheet, they also discovered a tuft of red carpet fibers – threads of evidence, which led them straight to the killer.

The news of a flight attendant's brutal murder prompted the son of a victim who had been killed five years earlier to contact the police. The MO of both murders was remarkably similar, and analysis of the biological evidence from the crime scenes proved that these were serial killings.

A two-man shrimp boat sank when a fast-moving, violent storm struck the Louisiana coast. The captain drowned, and the deckhand was rescued fourteen hours later. He told the Coast Guard that the captain's foot had become entangled in the fishing nets; they tried frantically to free him, but they failed. The deckhand was considered a hero until the captain's body was found. Eventually, the public discovered that he was coerced into confessing to the captain's murder.

When a wealthy real estate tycoon went missing, it appeared to be foul play. He had been aware that he was in danger. In his will, he left instructions regarding what was to happen if he died under violent circumstances – instructions which were carried out after a hiker came across a bullet-ridden skull.

The cold-blooded murder of an American tourist in a Mexican resort in 1991 focused law enforcement resources on both sides of the border. At first glance, the motive appeared to be robbery, but careful analysis of the forensic evidence pointed to something much more sinister.

The investigation of the kidnapping of a prominent banker's wife led police on a wild goose chase, tracking down disgruntled bank customers and examining computer fonts. An unexpected discovery made by an entomologist resulted in a new suspect, and the realization that ordinary office equipment can leave behind extraordinary clues.

In the middle of the night, a neighbor watched in horror as a man stabbed his wife, pushed her into the swimming pool, and held her head under water. When questioned by the police, the husband not only had no explanation for his actions, but he also had no recollection of the crime. A jury would have to decide between the evidence at the scene and the mysteries of the mind.