HLN

Using an anonymous letter and geographical profiling, investigators close in on a serial rapist, and a cleverly obtained DNA sample confirms their suspicions.

When a young boy has serious respiratory problems and his father shows signs of early Alzheimer's disease, a chance encounter with a stranger kicks off an investigation into the cause.

Police in St. Petersburg, Fla., use cell phone mapping, wiretapping and a host of forensic evidence to find a surgeon's killer.

A woman wins her release after being imprisoned for allegedly killing her mother in a car fire.

Authorities are able to apprehend a kidnapper because he allowed his victim to write a will on a telltale pad of paper.

Experts debate whether an apparent heart attack victim died from natural causes or alleged poisoning by his girlfriend.

When a 12-year-old was found dead in her home, police were left clueless until a string of burglaries months later. A trail of stolen goods may help solve a murder.

When 15 year-old Marlene Miller was murdered, it would take 24 years and several retrials before forensic scientists discovered the evidence to bring her killer to justice.

Detectives use a forged signature to find a woman's abductor.

A woman is killed two days before she was scheduled to testify against a man accused of assaulting her and the prime suspect has an alibi.

A serial killer terrorizes a small Texas town.

A mysterious murder in an upscale community is solved by cell phone forensics.

The anchors share the latest stories about significant events that take place across the world and interview prominent figures.

The anchors share the latest stories about significant events that take place across the world and interview prominent figures.

The anchors share the latest stories about significant events that take place across the world and interview prominent figures.

After the brutal slaying of a young couple on a road trip, the victims' families begin receiving disturbing letters.

The unexpected and strange death of a health conscious woman prompts an investigation.

After a young mother is found brutally murdered in her home, investigators find startling clues on her cell phone that could lead to her killer.

An amazing new forensic tool turns a cold case around.

A gruesome find in a small town church sends investigators searching for a killer.

An insurance agent is shot execution style in his office, but the killer leaves no fingerprints, and there are no murder weapon found at the scene; then investigators discover a critical clue invisible to the naked eye that cracks the case.

A healthy, young mother mysteriously dies after a minor traffic accident triggering an investigation.

Investigators search for clues after a body is discovered in a watery grave.

A bite mark is all the evidence needed to convict a suspect who was robbing tourists in Florida.

Technology able to analyze human bite-marks yields information on a woman's death.

A death in Pennsylvania is strikingly similar to one in North Carolina.

When a nurse starts experiencing a variety of flu-like symptoms, she discovers that she is HIV-positive; she learns that her infection was not accidental.

time of death becomes pivotal when a pregnant woman is found murdered in her air-conditioned bedroom.

An obscure print found at a crime scene.

A diner in a small town, an endocrinologist and a forensic botanist help destroy a prime suspect's alibi.

Neighbors do not hear the gunshots when a union official is killed in his home.

A man tells police he shot an intruder who murdered his wife; forensic evidence leads police to re-examine the man's motives.

A police officer claims his estranged wife's shooting death was a suicide, but investigators think it was a murder.

When fire fighters find a family dead inside their home, it appears to be a murder-suicide; clues at the scene lead investigators to believe otherwise.

A couple's murder leads investigators into the world of white supremacists and a string of hate crimes.

A rare gun and a victim's beloved dog help investigators trying to solve a multi-year long murder case where most of the witnesses were admitted drug users.

A search in Virginia's DNA databank reveals the identity of a news producer's murderer.

A homicide detective claims his wife accidentally shot herself in the head, but the evidence indicates otherwise.

Officials probe the death of a woman investigating the possible side effects of the drug she was prescribed for bipolar disorder.

A chip of stainless steel brings a killer to justice 20 years after a woman's body is found in a ravine.

An 11-year-old girl is sexually assaulted and shot twice at close range.

time of death becomes pivotal when a pregnant woman is found murdered in her air-conditioned bedroom.

An obscure print found at a crime scene.

A diner in a small town, an endocrinologist and a forensic botanist help destroy a prime suspect's alibi.

Neighbors do not hear the gunshots when a union official is killed in his home.

A man tells police he shot an intruder who murdered his wife; forensic evidence leads police to re-examine the man's motives.

A police officer claims his estranged wife's shooting death was a suicide, but investigators think it was a murder.

When fire fighters find a family dead inside their home, it appears to be a murder-suicide; clues at the scene lead investigators to believe otherwise.

A couple's murder leads investigators into the world of white supremacists and a string of hate crimes.

A rare gun and a victim's beloved dog help investigators trying to solve a multi-year long murder case where most of the witnesses were admitted drug users.

A search in Virginia's DNA databank reveals the identity of a news producer's murderer.

A homicide detective claims his wife accidentally shot herself in the head, but the evidence indicates otherwise.

Officials probe the death of a woman investigating the possible side effects of the drug she was prescribed for bipolar disorder.

A chip of stainless steel brings a killer to justice 20 years after a woman's body is found in a ravine.