SKAGIT COUNTY, Wash. -- Detectives on Wednesday returned to the home that belongs to the family of a woman who claims she had an affair with Jeremy Sully, the Ferndale High School track coach who was found dead.

The Skagit County Sheriff's Department served a warrant for a DNA sample and fingerprints of a man who lives at the house.

Deputies also searched the couple's back yard using metal detectors but would not elaborate on what they were looking for or whether they found anything significant.

The man and his wife have both been termed persons of interest in the case, and their home had been searched twice before prior to Wednesday.

Last month detectives uncovered a large amount of ammunition, several guns and computers. They also found a small amount of marijuana.

Scully, 38, disappeared while driving from his Bellingham apartment to the couple's house in Alger. His body was later found near his abandoned car on Blanchard Mountain.

After interviewing the persons of interests, detectives said they do not believe Scully's death was the result of a random crime.

"These are people that we have been terming 'persons of interest,'" Sheriff Will Reichardt said. "They are still persons of interest. No one has gone into custody. We're talking to them and we are just trying to gather more information."

Scully's mistress came forward after his disappearance and after admitting to police that she was having an affair with him, she directed them to his empty apartment. The woman told police said she did not hear from Scully all day on the day he disappeared, which was very unusual.

On the same day, when she called home to let her husband know that she was headed home from work, the woman said he asked her to pick him up at the Squires Lake Trailhead off of Old Highway 99 near the Whatcom County line.

According to police documents, the woman later learned her husband had invited Scully to their home to work on the roof on the day he disappeared. Her husband told police he had communicated with Scully via messages on the Internet.

While being questioned by Bellingham police, the man alluded to the fact that Scully was dead, the documents said.

Reichardt said Sully's body was found Sunday by hikers in a rugged area of Blanchard Mountain, some 200 yards off the main road through thick underbrush. The hikers reported the discovery to a Whatcom County sheriff's deputy who was in the area searching for Scully.

Scully's car was found abandoned on Interstate 5 near Lake Samish, about 8 miles from where the body was located.

An autopsy showed Scully died of a gunshot wound to the head.

On Tuesday, detectives revealed that Scully belonged to a Web site whose members meet for sex. Deputies said Scully's activities on the site AdultFriendFinder.com may or may not be related to his disappearance.

Scully coached pole vault at Ferndale High School for eight years. He also worked as a substitute teacher at the school and helped coach pole vaulting at Western Washington University.