PIERRE, S.D. (KELO) — A mystery surrounding a man’s identity has been solved. 

On August 9th, 1976, a man’s body was found floating in the Missouri River near Pierre.

The body was in an advanced state of decomposition, and there was no personal identification on the person, according to the South Dakota Attorney General’s Office. 

Partial fingerprints were taken, but without anyone to compare them to, no match could be made at the time.

An autopsy revealed a probable cause of death by drowning, and there was no evidence of foul play, according to Attorney General Marty Jackley.

After all efforts to identify the man failed, he was buried at the Riverside Cemetery in Pierre. 

His grave marker read “Unknown Man.” 

Unknown man marker
Unknown man marker | Courtesy: Office of South Dakota Attorney General

In 2020, the cold case was reopened by Detective Trevor Swanson of the Pierre Police Department. 

The body was exhumed in October 2021 and samples were collected in order to get a DNA profile. 

In 2022, Swanson remained on the case as special agent for the South Dakota DCI.

The unknown man’s DNA profile was compared to results found in genetic genealogy databases. 

The AG’s office says it resulted in a potential match for 39-year-old Stephen Earl Boice, whose last known address was Seattle, Washington. 

Only known photo of Stephen Boice, who went by Earl
Only known photo of Stephen Boice, who went by Earl | Courtesy: Office of South Dakota Attorney General

Investigators obtained a fingerprint card that had been collected from Boice in the 1960s.

It was compared to the fingerprints from the body found in the water. 

The South Dakota Forensic Lab determined both sets of fingerprints were made by the same person. 

Investigators contacted Boice’s closest living relatives. He was reinterred at Riverside Cemetery last fall at their request. 

A permanent headstone was placed at the gravesite in April.