21 Solved in ‘21 : Day 9 : Siobhan McGuinness
5-year-old Siobhan McGuinness went missing on Feb. 5, 1974. She had been walking the short distance home from a neighboring friend’s house around dinnertime in Missoula, Montana when she vanished. When she didn’t return home, several search parties were organized. The search parties continued overnight, but it was snowing, and any tracks or clues that may have aided in locating the young girl were quickly obscured beneath the snow.
2 days later on February, 7th, 1974, Siobhan McGuinness was found dead, having been brutally murdered. Her body was located near the Turah exit on Interstate 90 in a culvert. Along with making the search for Siobhan more difficult, the snowy conditions also made discovering who killed her nearly impossible.
Over the years, the Missoula Police Department continued to work an investigation into the murder, but without today’s technological advances, any leads dried up, and all investigation led nowhere.
In 2020, the Missoula Police Dept, the Missoula County Sheriff’s Office, and members of the FBI teamed up to use the newest DNA technology for Siobhan’s case. This technology was genealogy.
Siobhan’s clothing was sent to Bode Technology for DNA extraction. Due to the conditions at the time of her murder, as well as the time past, there wasn’t much DNA left. However, there was just enough– less than half a nanogram– to do the necessary testing.
Othram lab, the same lab utilized in the case of Stephanie Isaacson, uses Forensic-Grade Genome Sequencing which allows them to build DNA profiles from even the smallest, most degraded quantities of DNA.
This process allowed investigators to tie the DNA back to a family member, who had submitted their DNA to a consumer database. From there it was determined that Siobhan’s killer had been someone passing through the area. The man had his own family who had no idea what he had done, but were cooperative with law enforcement, and confirmed the timeline, even matching his car to a vehicle description given by witnesses at the time. Siobhan’s killer died in 2012. He had no prior criminal history, but his DNA has been provided to the FBI Violent Criminal Apprehension Program.
Both Siobhan’s mother and father were alive to see her case finally solved. Siobhan was described by her father as “beautiful and amazing.” She was only 5 years old, and had an entire lifetime ahead of her.
If you would like to help with the closing of cold cases like Siobhan’s you can go to dnasolves.com, a website run by Othram Inc. There you can upload your DNA data, or make a financial contribution.