Earlier this year, investigators learned that the suspect, Harry "Nicky" Nickerson, had confessed to a family member minutes after the murder.

Investigators identified the killer of a school teacher stabbed in the chest at a California high school in 1978, revealing the then-teen confessed to a family member.

Dane County Sheriff’s Office Detectives Brian Shunk and Sabrina Sims told ABC News’ Ryan Smith they believed Krista and Bart Halderson were killed in the basement of their Wisconsin home.

Over 40 years after a 24-year-old man was killed in rural Iowa, a suspect has now been arrested in connection to his murder, officials said.

Michael Schappert, 64, was arrested for the murder of Ronald Lee Novak, 24, who was brutally killed on Dec. 23, 1983, in rural Walker, Iowa, officials announced on Wednesday.

"We know who she is now. We have a name. We just want to find out what happened to her,” said Rob Baker, the deputy district attorney for Santa Clara County.

The Santa Clara County District Attorney's Office said it confirmed the identity of the victim by comparing her granddaughter's DNA to crime scene evidence.

A DNA sample helped identify the suspect as Ricky Lee Stallworth, a 27-year-old Air Force airman at the time of the murder, police said.

Allen Gould is being held without bail on charges including first-degree murder and tampering with physical evidence, prosecutors said.

Over 50 years after a mom was killed and her daughter was left abandoned next to her mother's body, the young mom's cold case murder has been solved.

Human skeletal remains were discovered Tuesday outside Chicago. Police say they could belong to a Chicago area woman whose family said has been missing for 42 years.

Human skeletal remains were discovered Tuesday outside Chicago. Police say they could belong to a woman who has been missing for 42 years.

A man has been arrested in a woman's 1979 cold case murder after investigators used genetic genealogy to zero in on his identity, police in Maryland announced.

A man has been arrested in a woman's 1979 cold case murder after investigators used genetic genealogy to zero in on his identity, police in Maryland announced.

Fmr. Beaumont Police Officer Carman Apple told David Muir she attended college with Catherine Edwards, the 31-year-old murdered in her townhouse. "She was so full of life," Apple remembered.

Nearly 25 years after Cathy Swartz was murdered, investigators were able to use advancements in DNA technology to re-examine fingerprint evidence initially collected at the crime scene.

David Muir visited David and Kristen Mittelman at Othram Inc.'s facility in The Woodlands, Texas, as part of his reporting on the 1988 Cathy Swartz and 1995 Catherine Edwards murder cases.

Nearly two years after the insurance agent’s murder, investigators received lab results from a touch DNA sample taken from inside Bob Eidman’s back pants pocket.   

Fifty years ago, she was on her way to try to blow the whistle on nuclear safety. But she never made it.

Nearly 46 years after a double homicide, a fingerprint from a taxi license application has led to a suspect's arrest, officials in western Massachusetts announced.

Nearly 46 years after a double homicide, a fingerprint from a taxi license application has led to a suspect's arrest, officials in western Massachusetts announced.

A 84-year-old man has been arrested for a cold case murder from 50 years ago after he was linked to the case with genetic genealogy, authorities said.

Mary Schlais' suspected killer, 84-year-old Jon Miller, was identified through genetic genealogy, according to authorities.

Suspected 1970s serial killer Bruce Lindahl has now been identified as the culprit in a 1979 cold case murder in Illinois, authorities announced Wednesday.

Suspected 1970s serial killer Bruce Lindahl has now been identified as the culprit in a 1979 cold case murder in Illinois, authorities announced Wednesday.

Genetic genealogy led authorities to charge Dana Shepherd in the 1993 rape and murder of Carmen Van Huss in Indiana.

A man has been arrested in the 1993 rape and murder of a 19-year-old in Indiana after he was linked to the case through genetic genealogy, authorities said.

DNA evidence from a discarded cigarette helped investigators solve the cold case murder of a 33-year-old, over 44 years after it was committed in Washington state.

Ruth Buchanan, 52, was killed when a driver ran a red light on Dec. 29, 1989.

Ruth Buchanan was fatally struck when a driver ran a red light, police said.

Susan Leigh Wolfe, 25, was found dead of a gunshot wound to the head in 1980.

A warrant was issued for a 78-year-old man in connection with a murder committed 44 years ago after genetic genealogy helped investigators identify him as a suspect.

A 1986 cold case murder of a teen has been solved after a DNA match led investigators to a convicted serial killer on death row.

The 1986 slaying of a 19-year-old woman whose body was found dumped in South Pasadena has been linked to a serial killer who was convicted of murdering 12 women in Riverside County.

Police recently reopened the unsolved case from 1987 and used DNA to identify the mother.

A woman linked by DNA has been arrested for the murder of her newborn 37 years after the baby girl was found dead in a dumpster in California, authorities said.

DNA has identified a suspect in the 1996 cold case murder of a 15-year-old girl in Montana.

The Gallatin County sheriff said authorities found a DNA match linking Paul Hutchinson to the 1996 murder of 15-year-old Danielle Houchins.

Warren Luther Alexander, 73, is being held without bail after being charged in the slayings of three women who were strangled to death in 1977 in California, authorities said.

A man already in custody has been arrested in the murders of three young women who were strangled to death in 1977 in California, authorities said.

Albert Lauro Jr., 57, was identified as a suspect of the 1991 murder of a 23-year-old woman in Hawaii.

Thirty-four years after a brother and sister were murdered, a man has been indicted in the slayings when he was linked to the cold case via DNA.

A Georgia man has been indicted in the double stabbing deaths of a brother and sister in 1990 after he was linked to the cold case via DNA, prosecutors said.

A convicted serial rapist has been identified as the suspect in the 1996 double murder of two women in a Virginia national park, federal authorities said.

A suspect has been identified in a double murder from May 1996 in Shenandoah National Park, Virginia.

After years of dead ends and long legal battles, Marlene Warren's son said he feels that he is at peace following the plea deal of the "killer clown" of Wellington.

Massachusetts authorities are searching for a newly identified suspect in two rapes from 1989.

Stephen Paul Gale, 71, is wanted on four counts of aggravated rape, two counts of kidnapping and one count of armed robbery.

“20/20” explores the multi-decade investigation and conviction of William Lewis Reece, who was linked to multiple murders

A Virginia man has been arrested in connection with the cold case murder of a 32-year-old woman in 1986.