The Latest on the investigation into the killing of a rural Washington state couple (all times local):

5:35 p.m.

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.

____

1:07 p.m.

Sheriff's detectives in Washington state say they've arrested the elderly parents of two brothers accused of fleeing to Mexico after killing a couple and burying their remains in a remote forest clearing.

The Snohomish County Sheriff's Office said Tuesday it arrested 81-year-old Clyde Reed and 77-year-old Faye Reed in Ellensburg for investigation of rendering criminal assistance. Investigators said that they admitted providing the vehicle in which their sons, John and Tony Reed, fled the state and giving them money.

Tony Reed turned himself in at the U.S.-Mexico border last month and led authorities to the grave of 45-year-old Patrick Shunn and his wife, 46-year-old Monique Patenaude. The two were former neighbors of John Reed in Oso, a rural community northeast of Seattle that was devastated in a 2014 landslide.

John Reed remains at large.