PORTLAND, Ore. (KOIN) — Authorities said a second suspect was arrested on Wednesday in connection to a murder where evidence of an explosion and human remains were found scattered around a Kelso property in July.

Jerome Markert, 47, was arrested for the killing of 51-year-old Alan Nielsen and is facing charges of first-degree murder, prohibited explosive devices, unlawful disposal of human remains and second-degree unlawful possession of a firearm. The last charge was a result of detectives recovering a gun during a search warrant in Oakville.

In July, the Cowlitz County Sheriff’s Office said detectives were tipped off there was a body off of Holcomb Road, just east of Interstate 5.

While searching the area, detectives said they found remains, later confirmed to be Nielsen’s, in and around a truck parked on the property. The Sheriff’s Office said both the truck and Nielsen’s body were “heavily damaged” in an apparent explosion.

The medical examiner determined Nielsen was shot on July 15. Officials believe the deceased was killed during an altercation with Jethro Welter, who was arrested on Oct. 27.

CCSO said the investigation is ongoing and anyone with information is urged to call Detective Troy Lee at 360-577-3092.