Y-STR DNA Explained Through a Real Cold Case #truecrimeshorts #truecrimeinvestigation #crimejunkies

Added: 2026-05-26

[00:00:00]Number two, YSTR DNA.

[00:00:03]Now, this type of testing zeros in on one thing and one thing only, the Y chromosome, which only exists in men.

[00:00:10]So, it can only trace DNA passed down from father to son. This type of testing can be particularly powerful when evidence has a mix of male and female DNA, like for example, what could be present in a sexual assault kit. By isolating the Y chromosome, labs can pull out just the male DNA from the sample. One chilling example of this?

[00:00:32]The 1991 yogurt shop murders in Austin, Texas. [music] At the time, YSTR testing was brand new, and the district attorney overseeing the case decided to give it a shot.

[00:00:45]Investigators believed that at least one of the victims in this case had been [music] sexually assaulted, and this test paid off. They pulled a partial male DNA profile from the evidence.

[00:00:55]>> [music] >> But, in the '90s, that profile didn't match anyone in the system, so the case went cold. Decades later, in 2025, everything changed when police received a report from a South Carolina state lab that linked the yogurt shop unknown YSTR profile to a known YSTR profile from a 1990 sexual assault and murder out of Greenville. The suspected killer?

[00:01:20]Robert Eugene Brashers, a known serial rapist and killer who had taken his own life back in 1999.

[00:01:27]From there, investigators were able to use other evidence to connect Brashers to the yogurt shop murders, bringing long-awaited answers to a case that haunted Texas and us crime junkies for more than 30 years.