Tracy police name victim’s cousin as suspect in 2009 homicide cold case (DNA)

Authorities said Mason died in a vehicle accident in 2015, a year before he was identified as the homicide suspect.

November 20, 2018

TRACY — The Tracy Police Department has closed an almost decade-old homicide cold case, but said the suspect is dead.

Police announced this week that 72-year-old James Mason is the lone suspect in the killing of his cousin, Clayton "Cotton" Riggins.

Riggins, 72, was found beaten to death on the living room floor of his West Carlton Way home on Nov. 17, 2009. Antique guns and collectible coins were missing from the residence.

Tracy police immediately ruled the death a homicide, but a killer had not been identified.

Police said in 2016 a suspect was identified using DNA evidence, and Tracy police and the San Joaquin County District Attorney's Office reopened Riggins' case.

The recent investigation led detectives to single out Mason, who was 63 at the time of the slaying, as the only perpetrator, according to a news release form Tracy police. Mason and Riggins, who was a retired railroad worker, were cousins.

Police did not disclose a motive for the killing.

Authorities said Mason died in a vehicle accident in 2015, a year before he was identified as the homicide suspect.

Riggins, an Oklahoma native, lived in Tracy more than 60 years, according to earlier news reports. He served in the U.S. Air Force in Japan and then went on to spend 33 years working for Southern Pacific.

"In speaking with the victim's family, they are 'relieved' this case is now resolved," Tracy police said.

The Tracy Police Department acknowledged the Richmond-based Serologinal Research Institute — a nonprofit forensic DNA lab— the state Department of Justice lab and the District Attorney's office for their help with this case.