The Woman Nobody Reported Missing - Episode 46

The DNA Clue Hidden Inside a Parasite: The Murders of Jennifer Bastian and Michelle Welch

Two girls vanished from Tacoma parks in 1986 within weeks of each other. Investigators spent decades assuming the same man was responsible — until a forensic science breakthrough in 2012 proved they had two separate killers and had to restart the entire investigation from zero. How do you solve a cold case when the only lead is a microscopic parasite found inside a DNA sample nobody knew existed?

In this episode, we explore a Y-STR familial DNA test that returned only three possible last names from an entire national database, an FBI behavioral profile that included a specific intestinal parasite as an identifying biological marker, and the moment one suspect blurted a confession before investigators even told him what crime they were asking about. Were these two killers strangers to each other, or did they share the same hunting ground by design? The forensic science and the genealogy trail do not leave much room for coincidence.

Case Details

Victim: Jennifer Bastian, 13, student; Michelle Welch, 12, student.

Date: March 26, 1986 (Michelle); August 4, 1986 (Jennifer).

Location: Tacoma, Washington, USA.

Case Status: Both cases resulted in guilty pleas or bench trial convictions. Robert Washburn pleaded guilty to Jennifer's murder on January 25, 2019, and received 26.5 years. Gary Hartman was convicted at bench trial on March 22, 2022, and also received 26.5 years. Both men are currently serving their sentences.

Episode Key Points

- Investigators assumed one killer for over 25 years — a 2012 DNA comparison proved the two cases had entirely separate sperm profiles, forcing the investigation to restart from scratch.

- The FBI behavioral profile identified a specific intestinal parasite, Strongyloides stercoralis, whose larvae can appear in sperm — one of the rarest biological markers ever used in a criminal profile.

- Robert Washburn told FBI agents he didn't kill "that little girl" before investigators had named the victim, the crime, or the year.

- Gary Hartman told a coworker, upon realizing he was being followed by police, that he had done something terrible thirty years ago and believed he had finally been caught.

Jennifer Bastian, Michelle Welch, Tacoma Washington murders, Point Defiance Park homicide, 1986 cold case, forensic science, true detective, criminal minds, investigation, homicide, unsolved mysteries, murder, DNA genealogy, true crime English.