Prosecutors in Skagit County, Wash., have charged an Oregon man with first-degree murder in the slaying of a school track coach who reportedly was involved in a "swinger" lifestyle that included the defendant's wife.

Kenneth McBride was arrested Wednesday at his home in Lebanon, Ore.

He lived in Skagit County when Jeremy Scully, an assistant track coach and substitute teacher, was shot to death in April 2008.

Detectives served a search warrant at the home of McBride and his wife, Venessa, after Scully's body was found. They seized several firearms, among other items.

Court documents say Venessa McBride gave birth to a child in January 2009.

The documents say the child would have been conceived during a period when she had sexual encounters only with Kenneth McBride and Scully, and Kenneth McBride had undergone a vasectomy.