LOS ANGELES (AP) — Police used a tanklike vehicle with a battering ram to smash into a Southern California home and arrest the next-door neighbor of a couple living in a nudist community who were reported missing earlier this week, officials said Friday.

Officials believe the bodies of Stephanie Menard, 73, and her husband, Daniel, 79, are inside the residence, though they first have to shore up the home to make it safe to search, said Carl Baker, spokesperson for the Redlands Police Department.

“We are confident that they are deceased and that they are still here on the property,” Baker said. He did not release any information about a possible motive.

Later Friday, officials said searchers had found human remains in bags in a concrete bunker underneath the home. The remains were not immediately identified.

Michael Royce Sparks, 62, was booked into jail on suspicion of homicide Thursday night after being found under the house at Olive Dell Ranch, which is described as a residential RV park and family friendly nudist resort on its website. The rustic community is in hill country about 60 miles (96 kilometers) east of Los Angeles.

Baker did not know whether Sparks has a lawyer who can speak on his behalf. Online jail records showed he was ineligible for bail and was scheduled for a Tuesday court appearance.

A dog trained to find cadavers indicated the presence of at least one body somewhere under the house Friday morning, but officers were waiting to enter until a structural assessment determined whether the home was safe, Baker said at a news conference.

“We’re not going to send people in if there’s a danger of the structure collapsing on them,” Baker said, noting that the assessment might take hours to complete.