SKAGIT COUNTY, Wash. -- A man has been charged with murder in the case of a substitute teacher in the Ferndale School District who was found dead of a gunshot wound on Blanchard Mountain in late April, said the Skagit County Sheriff’s Office.

Kenneth McBride was arrested Wednesday morning has been charged with first-degree murder in the death of 38-year-old Jeremy Scully.

Police officers searched McBrides' home at least three times in 2008 and considered him and his wife “persons of interest.” Detectives said they had been waiting for computer forensics to come back and for several indicators before making an arrest.

According to a Skagit County Sheriff’s Office affidavit, McBride’s wife, Venessa, told detectives that she was having an affair with Scully and she said Scully was headed to the home to help Kenneth fix the roof when he vanished.

Detectives said that Kenneth McBride, Venessa McBride and Scully all took part in the “swinging lifestyle” and were a part of a sex swingers club.

As Venessa McBride and Scully’s relationship continued to grow, Kenneth McBride told her that he would become “unglued” if Scully ever tried to influence their relationship, documents stated.

Kenneth McBride had spied on his wife's computer, retrieving online chats between her and Scully that talked about them being in love, their sex and travelling together to Seattle without Kenneth’s knowledge.

In the days leading up to Scully’s death, Venessa McBride had told friends that she was unhappy in her relationship with Kenneth McBride and considering divorcing him. In one conversation she said to a friend online that “I told Ken last night that J and I are in love,” according to the affidavit.

On April 24, Scully was planning to meet with Kenneth McBride to fix his roof. His body was found several days later on Blanchard Mountain on April 27.

Just days after the crime, detectives searched the McBrides' home in Alger. They seized guns, drugs and ammunition inside. Police later discovered the ammunition recovered from the McBrides' home was consistent with that recovered from Scully’s body, the affidavit stated.

The affidavit also revealed that Venessa McBride had a baby in January, but that Kenneth McBride has a vasectomy because Venessa’s medical condition prohibited her from taking birth control.

Police calculated that 40 weeks back from January would mean the baby was conceived in April. She was only having sex with Kenneth McBride and Scully at the time, detectives said.

"We believe that the defendant did have a fairly strong motive for this homicide. We believe without a doubt that he's the person guilty of this," said Will Reichert of the Skagit County Sheriff's Office.

Scully was a substitute teacher in the Ferndale School District and also helped coach pole vaulters.

Kenneth McBride was arrested near his home in Lebanon, Ore., and is currently in an Oregon jail. It’s unknown when he’ll return to Skagit County.