20/20

Allison Feldman was a young woman living in Scottsdale, Arizona, whose life appeared to be taking off. Her career as a medical salesperson was thriving; she had a steady boyfriend, a loving family and a wide circle of friends. That all changed one evening in February of 2015 when Allison was found brutally beaten and sexually assaulted inside her home. Detectives interviewed the people closest to her, but none matched the most critical evidence: a clear, unknown DNA profile recovered from the crime scene. Allison's murder remained unsolved for years until advances in forensic familial DNA pointed investigators to a man with no known connection to Allison who held the clues to crack the case wide open.  "20/20" contributors David and Kristen Mittelman of Othram Labs, one of the country's preeminent forensics labs, share insight into how familial DNA works and how this crucial DNA evidence helped catch a killer. 

When 22-year-old Cati Blauvelt disappears, her loved ones immediately know something is wrong. After filing a missing person's report, family and friends begin searching locations in her Simpsonville, South Carolina, hometown. But when two male friends find Cati stabbed to death and hidden in the basement of an abandoned house, authorities become suspicious. It seems too convenient to detectives that these men would find Cati in the first place they looked. Eventually, authorities clear these friends and expand their search to other people in Cati's life. They discover that she had an estranged husband, Army recruiter John Blauvelt. Police find John's behavior in the wake of Cati's death strange, including bringing his new 17-year-old girlfriend, Hannah Thompson, to her funeral. In the weeks after Cati's murder, they continue to question John until he goes AWOL, fleeing the area with Hannah in tow. A few weeks later, Hannah turns up in Oregon, saying she wants to come home and telling police she has no idea where John has gone. John remained on the run for years until a tip led to his takedown and arrest in Medford, Oregon, where he lived under the alias Ben Klein. He was tried, convicted and sentenced to life in prison for murder and is appealing his conviction. Hannah pleaded guilty to obstruction of justice and misprision of a felony and received three years of probation. 

When two suitcases containing human remains are discovered along a Wisconsin highway, it sends shockwaves through the community. The key to unraveling the mystery lies with a 37-year-old woman named Laura Simonson who suddenly disappears, leaving behind only a note apologizing to her family. As investigators dig deeper, they uncover a disturbing online world involving BDSM and a former police officer known as "Mr. Handcuffs," whose role in Laura's disappearance raises troubling questions. 

On Sept. 7, 2012, UNC Chapel Hill sophomore Faith Hedgepeth was found murdered in her off-campus apartment, leaving her family and friends devastated and desperate for answers. Who would want to kill her? A devoted member of the Haliwa-Saponi tribe, Faith was known for her outgoing personality and vibrant social life. Thousands of potential suspects were investigated, and hundreds of DNA samples were tested, but despite the involvement of the FBI, state agencies and private investigators, the case remained unsolved for years. In 2016, there was a break in the case. Investigators turned to DNA phenotyping technology, with Parabon Nano Labs generating a composite sketch of a potential suspect whose ancestry was described as Native American and European or Latino. Still, years passed without an arrest. Then, in 2021, authorities announced a major breakthrough: Miguel Enrique Salguero-Olivares had been arrested in connection with Faith's murder after DNA collected during a DUI stop matched evidence from the crime scene. Although he had no known personal connection to Faith, he was reportedly working near her apartment around the time of her death. 

Following the jury's recent announcement of a guilty verdict against Salguero-Olivares, "20/20" correspondent Ryan Smith examines the murder of Faith Hedgepeth, the yearslong investigation that led to the arrest, and the DNA evidence that helped bring the case to trial. With the verdict just announced, the all-new report revisits the search for answers in a case that haunted Faith's loved ones for more than 13 years.