13-year-old Dario Cicolecchia disappeared from a small Swiss village in 1993. His body was later found in a cornfield, with signs of sexual violence. There was no apparent evidence at the scene, but microscopic examination revealed diatoms - single-celled organisms that live in and around water. Could the tiny diatoms help investigators solve the case? Hosts: Colleen O’Brien, Erica White. Audio Supervisor: Tommy O’Brien. Theme Music: 'The Drama' by Rafael Krux (orchestralis.net). RAINN (US) 1-800-656-4673 / https://www.rainn.org/. National Sexual Violence Resource Center (US) https://www.nsvrc.org/

A series of bombings rocked Salt Lake City in 1985. First, businessman Steve Christensen was killed by a bomb left outside of his office. Then Kathy Sheets was killed by a similar bomb at her home. At first, the motive appeared to be business - the second bomb was addressed to Kathy’s husband Gary Sheets, former business partner of Steve. When a third bomb went off, injuring documents dealer Mark Hofmann, the case became more complicated. Investigators would soon find themselves unraveling a web of forgeries and cover-ups, using forensic document examination to crack the case. Hosts: Colleen O’Brien, Erica White. Audio Supervisor: Tommy O’Brien. Theme Music: 'The Drama' by Rafael Krux (orchestralis.net).

This is a wild one! Elementary school teacher Joanne Chambers began receiving bizarre, threatening letters in 1993. Joanne was an unlikely target for harassment, and police could only come up with one suspect: Paula Nawrocki - another teacher at the school. Despite having only circumstantial evidence, police and prosecution went forward with a case against Paula. When DNA evidence was found on some of the letters, everything would change...We’ll also give you a lesson in typewriter technology and the history of stamp pricing! Hosts: Colleen O’Brien, Erica White. Audio Supervisor: Tommy O’Brien. Theme Music: 'The Drama' by Rafael Krux (orchestralis.net).

In 1986, Susan Snow died after taking Excedrin capsules contaminated with cyanide. Her death prompted a recall and an investigation, which turned up more bottles of poisoned pills. 2 of those bottles were at the home of Stella Nickell. Her husband Bruce had recently died, and Stella insisted his death be re-investigated in light of Sue’s death. When it was found that Bruce also died of cyanide poisoning, investigators worried there was a serial poisoner at work. The truth was that only one person committed the poisonings, and the identity of the killer would be revealed by some tiny green crystals. Hosts: Colleen O’Brien, Erica White. Audio Supervisor: Tommy O’Brien. Theme Music: 'The Drama' by Rafael Krux (orchestralis.net).

In July 1991, a janitor discovered burned remains in a dumpster in Vancouver. The remains were so damaged by the fire that dental records were the only possible method of identification. The remains were those of a missing woman named Mary-Lynn Breeden. Bank surveillance footage and questioning an accomplice led investigators to the man they believed killed Mary-Lynn. To convict him, scientists would have to find a source of DNA that had never been used before. Hosts: Colleen O’Brien, Erica White. Audio Supervisor: Tommy O’Brien. Theme Music: 'The Drama' by Rafael Krux (orchestralis.net).

In 1984, a car bomb nearly killed Margaret Backhouse, wife of Graham Backhouse - a farmer in Horton, England. Less than two weeks later, Graham was involved in a fatal altercation with neighbor Colyn Bedale-Taylor. Graham claimed that Colyn took responsibility for planting the bomb and then attacked him, but forensic analysis of the crime scene would cast doubt on Graham’s entire story. Hosts: Colleen O’Brien, Erica White. Audio Supervisor: Tommy O’Brien. Theme Music: 'The Drama' by Rafael Krux (orchestralis.net).

41-year-old waitress Peggy Carr fell mysteriously ill in late 1988. Her symptoms stumped doctors, until one noticed a sign that pointed to a terrible poison. Health officials ran extensive tests, and police conducted an undercover investigation to discover the identity of the person who would want to poison Peggy and her family. Hosts: Colleen O’Brien, Erica White. Audio Supervisor: Tommy O’Brien. Theme Music: 'The Drama' by Rafael Krux (orchestralis.net).

Ruby Morris went missing from Phoenix, Arizona in June 1989. Investigators found evidence of blood in the bedroom Ruby shared with her husband Earl, and a gun the couple owned was missing from the home. DNA testing would reveal dark family secrets, but it would ultimately also crack the case. Hosts: Colleen O’Brien, Erica White. Audio Supervisor: Tommy O’Brien. Theme Music: 'The Drama' by Rafael Krux (orchestralis.net). RAINN (US) 1-800-656-4673 / https://www.rainn.org/. National Sexual Violence Resource Center (US) https://www.nsvrc.org/

In November 1993, Hambleton couple Derek and Eileen Severs disappeared. Their adult son Roger told police they’d gone to London, but there was no evidence of that. The clues to finding the Severs were small and seemingly insignificant - a few drops of blood, some green fibers, and dried mud on a car - but with the right forensic analysis, they would tell investigators everything they needed to know. Hosts: Colleen O’Brien, Erica White. Audio Supervisor: Tommy O’Brien. Theme Music: 'The Drama' by Rafael Krux (orchestralis.net).

In 1984 in Tampa, Florida, 10 women were murdered over several months. There were similarities in victimology and M.O., and identical red fibers were found on several of the victims. Along with fiber evidence, details provided by a brave 17-year-old survivor would lead to the arrest of a serial killer. Hosts: Colleen O’Brien, Erica White. Audio Supervisor: Tommy O’Brien. Theme Music: 'The Drama' by Rafael Krux (orchestralis.net). RAINN (US) 1-800-656-4673 / https://www.rainn.org/. National Sexual Violence Resource Center (US) https://www.nsvrc.org/