‘It’s A Big Deal’: DNA Solves 46-Year-Old Murder Of 5-Year-Old Girl

Decades after Siobhan McGuinness was sexually assaulted, stabbed to death, and left in a drain culvert, investigators point to Richard William Davis as her killer.

Digital Original
DNA Solves 46-Year-Old Murder Of 5-Year-Old Siobhan McGuinness
oxygen Insider Exclusive!

Create a free profile to get unlimited access to exclusive videos, sweepstakes, and more!

Sign Up for Free to View

The decades-old brutal murder of a 5-year-old year Montana girl has been solved, finally bringing some closure to her family. 

Siobhan McGuinness vanished on Feb. 5, 1974, just blocks away from her home in Missoula, a Missoula Police Department press release obtained by Oxygen.com stated. Her body was found in a snowy drain culvert near an interstate exit a few days later. She had been sexually assaulted and stabbed to death, private DNA lab Othram Inc said in a press release.

“Over the course of the next 46 years, the Missoula Police Department has periodically worked the case, assigning several investigators who have followed up on any/all leads, reviewed evidence, and conducted interviews trying to find answers,” the Monday press release from MPD stated. “Today we have one.”

Siobhan Mcguinness Pd

McGuinness’ killer has now been identified as Richard William Davis, investigators announced at a Monday virtual press release. Davis would have been 32 when the child was murdered and was thought to have been traveling through the area at  that time.

Davis will not face jail time — he died in Arkansas in 2012, Missoula Police Chief Jason White said during the presser.

Richard William Davis Pd

Advances in DNA led to the case’s closure. Othram used DNA extract from the crime scene to produce a genealogical profile which in turn led to Davis’ identification. 

"It is critical to solve these sexual assault cases to secure justice for the victims, but also to identify other possible victims,” David Mittelman, CEO of Othram, told Oxygen.com.  “If CODIS does not yield an answer then we have to use other forensic DNA tools to help solve a case."

CODIS is the FBI’s DNA database, but only some people with criminal backgrounds are included in CODIS. Since recent advancements were made in DNA technology, genetic genealogy work in private labs has led to the identification of killers who were not included in the CODIS database, like the Golden State Killer. Recently Othram research led to breaks in the cases of murdered cheerleader Carla Walker and slain Canadian child Christine Jessop.

The identification of McGuiness' killer has brought some relief for the child's family. 

“We are all relieved with the positive identification of Siobhan’s murderer and our prayers go out to his family [Davis' family] hoping that they will have the same sense of closure we have so long awaited,” her father, Stephen McGuiness, said during the Monday press conference. His voice broke as he spoke and his daughter Oona, half-sister of Siobhan, consoled him.

“It really means the world. My dad never thought that he would see this happen in his lifetime,” Oona said. “It's a big deal. It's a really big deal for us, and it's a huge deal for the Missoula community. This affected almost everybody that lived there at that time and probably still some today.”

Othram described the slain child as “bright and energetic.”

Related Stories

Crime Time is your destination for true crime stories from around the world, breaking crime news, and information about Oxygen's original true crime shows and documentaries. Sign up for our Crime Time Newsletter and subscribe to our true crime podcast Martinis & Murder for all the best true crime content. 

You May Also Like...
Recommended by Zergnet