Missing Coast Guardsman Russell Matthews Found, But 'Incoherent'

Petty Officer First Class Russell Matthews, gone missing for almost four months, showed up at his Hawaii home over the weekend. (U.S. Coast Guard)

A Coast Guard rescue swimmer who disappeared more than three months ago following an investigation into his alleged use of illegal drugs, mysteriously has returned to his Hawaiian home, incoherent and offering little clues as to where he had been, authorities said.

Petty Officer First Class Russell Matthews, a 17-year-veteran of the Coast Guard, was reported missing near Oahu's Kaena Point in October. His fellow guardsman along with police launched a three-day search of the water and along the beach, but found nothing.

U.S. Coast Guard

Petty Officer First Class Russell Matthews,... View Full Size

U.S. Coast Guard

Petty Officer First Class Russell Matthews, gone missing for almost four months, showed up at his Hawaii home over the weekend.

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At the time of his disappearance, Matthews was under investigation for using marijuana.

"He is an individual that is really dedicated to Coast Guard. He does Search and Rescue for a living," Coast Guard spokesman Lt. Gene Maestas told ABC News affiliate WKI-TV

"In 28 years of Coast Guard service I've never heard of a case like this," he said.

Matthews went missing nearly a year after his wife Carla died of a gunshot wound to the head. A medical examiner ruled the death a suicide.

According to officials, Matthews reappeared Sunday but was "incoherent" and was taken by police to a hospital where he is being observed. Once Matthews was found, police closed his case. It is not illegal to be a missing person.

Maestas said Matthews has not indicated where he was in the past three months, or why he ceased to be in contact with family, friends or the Coast Guard.