According to police, Brad Lee Davis said a fight broke out with his stepfather, Denver St. Clair, after St. Clair insulted Davis' mother. According to court documents, Davis admitted to pulling St. Clair's underwear over his back and head, allowing the elastic band to wrap around his neck. Police also reported blood splatter on the walls.
Once St. Clair stopped breathing, Davis called 911. Officials say he told detectives he gave his stepfather an atomic wedgie.
Court papers also show Davis planned on assaulting St. Clair, but not necessarily killing him.
Davis is being held without bond. A formal charge is expected to be filed at a hearing later this month.
Our sister station KFSN-TV in Fresno contributed to this report.