Cold cases that baffled investigators get solved with help of cutting-edge DNA tech

In 1988, 19-year-old Cathy Swartz was a young mother living with her fiancé Mike Warner and her 9-month-old baby Courteney in Three Rivers, Michigan. On Dec. 2, Warner returned home from work to find his fiancée dead in the couple's bedroom; she had been strangled and her throat had been cut.

In the baby's room, Courteney was standing in her crib, unharmed.

Now a mother herself, Courteney Swartz reflected on her mother's tragic death in an exclusive interview with David Muir for "20/20."

"I'm 100% convinced she was trying to save her baby because I feel like she would've just ran outside and yelled . . . but I was upstairs and she wasn't going to leave that apartment without me," she said.

Though Cathy Swartz's killer left behind a fingerprint on a pink phone and a bloody footprint in the bathroom, police ran thousands of prints without finding a match to the prints left at the crime scene.

Similarly, the suspect's DNA left on the phone generated no matches in CODIS, the national criminal offender DNA database. Detectives worked the case for decades without identifying the perpetrator as Cathy Swartz's family waited for answers.

In a new "20/20" episode, "The Code Breakers," airing March 7 at 9 p.m. ET on ABC, and streaming the next day on Hulu, David Muir explores the innovative DNA technology Othram used to crack the murder cases of two young women, Catherine Edwards and Cathy Swartz, that haunted their small communities for decades.

"20/20" features Muir's exclusive interviews with Cathy Swartz's daughter, law enforcement, as well as interviews with prosecutors and a prior victim speaking out for the first time on television about her assault by Edwards' killer.

Now a state-of-the-art forensic lab near Houston, Texas -- which is focused solely on partnering with law enforcement on cold case investigations -- is gaining attention for its ability to use powerful DNA testing technology to help crack seemingly unsolvable cases.

Othram, Inc. has been linked to some of today's most talked about criminal investigations, including the Gilgo Beach serial killings and the Idaho college student murders.

"We can identify almost any perpetrator anywhere from any case," Othram Chief Business Development Officer Kristen Mittelman told ABC News' David Muir as they spoke inside the company's lab. For the families of murder victims like Cathy Swartz, the answers that Othram is helping provide come after decades of waiting and wondering.

Across the country in Beaumont, Texas, Othram partnered with investigators on the case of beloved schoolteacher Catherine Edwards after the case hit a dead end. On Jan. 14, 1995, 31-year-old Edwards failed to show up for lunch with her parents and identical twin sister, Allison Brocato. When the family checked Edwards' home, they found a chilling scene: Edwards was dead, slumped over her bathtub with her hands handcuffed behind her back.

The first officer on the scene, Carman Brown Apple, recalled arriving and recognizing the victim's name. "I went to college with her. We were in sororities together," Apple told David Muir outside the townhome where Edwards was found. "She was so full of life . . . and to come to the scene and then suddenly realize it was Mary Catherine, it just knocked me for a minute."

Although police collected a sample of the killer's DNA left on the bedspread and from a rape kit, there were no matches for the suspect in CODIS and the investigation soon stalled.

More than three decades later, local law enforcement agencies in Beaumont and Three Rivers separately partnered with Othram as a final effort to identify a suspect in each of the murders.

Othram's powerful DNA sequencer helped build the suspects' DNA profile from microscopic samples of evidence. That DNA profile was then compared to other publicly available profiles in specific databases, like GEDMatch PRO, which allow law enforcement searches. Investigators were then able to build family trees for the suspected killers.

In the case of Edwards, Beaumont detective Tina Lewallen and genetic genealogist Shera LaPoint helped create a family tree that led to a suspect named Clayton Foreman, who had grown up in Beaumont and attended the same high school as the victim, Edwards. When investigators finally became aware of Foreman, he was living in Ohio and working as a rideshare driver.

Investigators learned Foreman not only attended the same high school as Edwards, she and twin sister Brocato were also bridesmaids in Foreman's wedding to his first wife in 1982. Investigators also discovered that Foreman had a prior record for aggravated assault in 1981. According to documents filed in Jefferson County Texas' District Court, Foreman admitted to the sexual assault of a woman named Paula Ramsey but pleaded guilty to aggravated assault and received three years of probation.

Routine DNA collection of offenders by law enforcement for the Combined DNA Index System (CODIS) did not begin until the mid to late 1990s, according to the FBI and the DNA Identification Act of 1994. Clayton Foreman's DNA did not exist in CODIS when Edwards' murder occurred in 1995. Investigators noted that Foreman's assault of Ramsey bore striking similarities to Edwards' murder, but it wasn't until 2020 when investigators discovered the record of the 1981 file.

Ramsey said she was initially reluctant to go to the police but summoned the courage to do so about a week after the assault.

"I just felt awful and shameful," Ramsey told "20/20" in her first and only interview about the 1981 attack. "I was just like, 'I can't, I'll never tell anybody what happened.' I was kind of like, I don't know if anybody would believe me. Is it my fault? Was it my fault?"

During Foreman's 2024 trial for the murder of Edwards, Ramsey took the witness stand and offered emotional testimony about why she chose to testify about the attack.

"I wanted to see justice done for her [Catherine Edwards]," Ramsey said. Foreman was convicted of Edwards' murder and sentenced to life in prison. He will be eligible for parole after 30 years in prison and is appealing his conviction.

In the Cathy Swartz case, Othram's genetic genealogy team built a DNA profile and subsequent family tree for the suspected killer based on the DNA sample provided by police. This helped investigators narrow down their potential suspect to four brothers who grew up in the Three Rivers area.

After further investigating, police cleared all of the brothers but one, zeroing in on 53-year-old Robert Waters.

Waters relocated after the murder and, in 2023, was residing in Beaufort, South Carolina. He ran a successful plumbing business and was married with children. Investigators learned that Waters knew Cathy Swartz's fiancé and briefly visited the couple's apartment a month before she was killed.

Detectives visited Waters in Beaufort and took his fingerprints and a DNA sample -- both were a match to the suspect's DNA and fingerprint left at the crime scene. Days after his 2023 arrest, Waters died by suicide in jail. Authorities found devotional pamphlets open to pages describing forgiveness in his cell.

"He's a coward. I mean, to take her away from all of us in the manner that he did, and then he got to go live his life," Cathy Swartz's childhood friend, Jennifer Outman, told "20/20."

Othram founders David and Kristen Mittelman believe the DNA technology they employed in the Edwards and Swartz cases will eventually become a routine part of criminal investigations.

"I think we're going to live in a world in this lifetime where there are no unidentified victims, victims that are voiceless. . ." Kristen Mittelman said. "I think we're going to live in a world where perpetrators are caught the first time they commit a crime and not . . . decades later."

"I have been living with this for 36 years," Courteney Swartz told "20/20." ". . . They solved this case with DNA, so I can close this book and open up my own book with my own kids. And there's no words for that."

If you are struggling with thoughts of suicide or worried about a friend or loved one, call or text the Suicide & Crisis Lifeline at 988 for free, confidential emotional support 24 hours a day, seven days a week.