Cold Case Solved

Sgt. Terry Preuninger, PIO


Thursday, March 26, 2020 at 7:52 p.m.


Spokane Police Department solves 35 years old murder with the help of genetic genealogy.

The tragic case of Marsi Belecz, a 12 year old Spokane girl who was raped and murdered in August of 1985 has been solved. Marsi had run away from home two days before her body was found underneath a boom truck in a junkyard in East Central Spokane. The young girl had been stabbed 31 times and her throat was cut.

After an exhaustive search for the killer, which included interviews with 257 people and identification of 87 possible suspects, the case went cold.

“Everybody that had this case did what they could do at the time, it just wasn’t possible due to technology to do anything more,” said Capt. Brad Arleth.

The case picked up again last year when SPD employed a company called Parabon NanoLabs that specializes in genetic genealogy. With DNA from the crime scene, Parabon built a picture of the suspected killer. The profile was put together by DNA analysis which determines how much, if any, DNA is shared between two individuals and estimates their family connection. In this case, genetic genealogy identified 4 possible suspects. Detectives obtained DNA from 2 of them with negative results. A third suspect was deceased but DNA obtained from his family indicated a match.

In March of 2020, SPD obtained a search warrant to exhume the body of the suspect and tests of his DNA indicated he was the person who raped and killed Marsi. The DNA match was about the highest count possible for certainty, 1.1 nonillion; (1,000,000,000,000,000,000,000,000,000,000).

The killer was Clayton C. Giese, born and raised in Montana. He was 22 years old at the time of the murder. He had a minor criminal record and died some 4 years later in a one car rollover crash. Detectives determined Giese did not know Marsi but believe he was at a party she attended the night she died.

“Justice in this case? Maybe not, the guy’s deceased, but closure, I think, for the family, the community. For people that remember that,” said Arleth.

For detectives, it’s a bittersweet end to a case. Solving it also means opening up old wounds and emotions for family members. Police offer their condolences to Marsi’s family and also credit Giese’s family for cooperating with the investigation.

“For the police to show up at your door and raise this issue of someone you buried a long time ago that you cared about a great deal, that’s tough for anybody,” said Sgt. Zac Storment. “I asked myself that — ‘how would I respond?”

This is the 9th cold case the Spokane Police Department has solved in the past decade. There are 113 unsolved murders in Spokane dating back to the late 1950’s. SPD is one of the few police departments in the state without a dedicated Cold Case Unit. Detectives work on average about 250 major crime cases a year between 9 detectives.

Capt. Brad Arleth; “It’s important for us to solve crimes. The more serious, like murder, the more important it is that we can bring resolution. We would like to be successful at solving all of our cases, and today we are thankful to have solved Marsi’s.”



Contact Police

Media Relations Contact

Officer John O'Brien
509.835.4568
jobrien@spokanepolice.org