The only person to survive Shasta County's largest mass murder is under arrest in Wyoming on suspicion of a sex crime.

Detective Sergeant Mark Trimble of the Casper, Wyoming, police department says 45-year-old Bruce Wulfert is in jail in lieu of $15,000 bail, accused of incest with a person who isn't being named.

Trimble says Wulfert faces up to 15 years in prison if he is convicted.

Wulfert had already gone to work last April when six members of his Happy Valley household were shot and burned in their home south of Redding.

Wulfert's fiancee and her 13-year-old daughter were among those killed. Shasta County investigators believe the killings were the result of a murder-suicide committed by Wulfert's fiancee's brother.