Siobhan McGuinness was a bright and energetic 5-year-old girl living in Missoula, a beautiful and quiet community in western Montana. One evening in early 1974, the tranquility of this peaceful community was shattered when Siobhan disappeared while walking home from her friend’s house. Search parties combed the area throughout the night, but as the hours passed, hope of finding the little girl plummeted with falling snow. Siobhan’s body was found two days later stuffed into a snowy culvert; she had been sexually assaulted and stabbed to death.
Throughout the decades that followed, the Missoula Police Department has maintained an expansive investigation in an effort to find Siobhan’s killer. With the community’s cooperation, the Missoula Police Department’s use of voluntary traditional forensic DNA testing has eliminated individuals, one-at-a-time, but leads were exhausted without a match. Earlier this year the Missoula County Sheriff’s Office and Missoula Police Department teamed up with FBI Division Counsel Steve Kramer and FBI Special Agent Steve Busch, the nation’s top law enforcement experts on the newest DNA technology that helped identify the Golden State Killer, in an effort to leverage this new tech to finally get answers. In a closely coordinated joint effort with Missoula Sheriff and Police Department personnel, the team set out to re-examine the case and apply forensic genomics technology to identify new leads.
The agency sent evidence to Bode Technology. Bode identified the best way to sample clothing that had been found in challenging, wet and cold environments. Despite the case being more than 35 years old, Bode was able to successfully extract sufficient DNA for testing at Othram. Othram applied their Forensic-Grade Genome Sequencing® process to the DNA extract to produce a genealogical profile from less than 400 pg of highly degraded DNA that remained from the 1974 crime scene. Division Counsel Steve Kramer and Special Agent Steve Busch used the profile to perform a genealogical investigation, in cooperation with Missoula law enforcement, ultimately identifying a candidate, Richard William Davis, that was independently confirmed as Siobhan's suspected assailant by traditional means.