Authorities said Tuesday they have found bodies believed to be a Washington woman and man who have been missing for six weeks and presumed killed.

Tony Clyde Reed, one of two brothers charged with the slayings of Monique Patenaude and her husband, Patrick Shu, provided information that led detectives to pinpoint the remote location near the couple's home Tuesday afteoon, Snohomish County Sheriff's Office spokeswoman Shari Ireton said at a news conference.

Authorities had been searching for the couple since they were reported missing April 12.

"We are waiting for medical examiner confirmation but we have reason to believe that they are Patrick Shu and Monique Patenaude," Ireton said.

The bodies were found buried in an area where the couple's vehicles were found by authorities weeks ago, about 50 miles northeast of Seattle near the town of Oso.

Ireton said authorities had searched in that area several times but getting specific information about where they were buried was what helped them make the discovery.

Reed appeared in Snohomish County Superior Court earlier Tuesday afteoon and entered not guilty pleas to two counts of first-degree murder and unlawful firearm possession in the case.

He tued himself in last week at the U.S.-Mexico border after a monthlong manhunt.

His attoey, James Kirkham, helped arrange the surrender. Kirkham told The Daily Herald in Everett, Washington, on Monday that his client tued himself in to answer the allegations against him.

"My client is iocent of the first-degree murder charges," the lawyer said. "He's here to defend himself."

Authorities are still searching for Reed's 53-year-old brother, John Blaine Reed.

John Reed and the couple were former neighbors. Authorities have said Reed, Patenaude, 46, and Shu, 45, had been involved in a property dispute.

Ireton said Tony Reed has been cooperating with detectives.