SEATTLE (AP) — Authorities have dropped murder charges filed against one of two brothers in the killings of a rural Washington state couple.

Tony Clyde Reed and John Blaine Reed were each charged with first-degree murder in the April disappearance of 45-year-old Patrick Shunn and his wife, 46-year-old Monique Patenaude, of Oso.

Sheriff's spokeswoman Shari Ireton said Tuesday that upon further investigation, detectives have determined that Tony Reed is "likely responsible only for rendering criminal assistance in the first degree." Investigators previously said they saw both victims' vehicles being driven up a logging road near where the bodies were eventually discovered.

The Snohomish County Prosecutor's Office on Tuesday dropped the murder charges against Tony Reed, who surrendered at the U.S.-Mexico border. He is now charged only with rendering criminal assistance.