A Washington man charged with killing a missing woman allegedly admitted to arresting officers that he had done so and told them her body was inside the motorhome where he had been living.

Chris Foiles, 42, was arrested in Idaho Falls, Idaho, on January 12, as CrimeOnline reported. Police said at the time they found enough evidence inside the motorhome to charge him with the murder of Megan Ashley Stedman, the 34-year-old mother of two.

Stedman was last seen on December 15 in the Bozeman/Livingston area of Montana. Idaho Falls investigators found the motorhome on January 12 and set up surveillance on the vehicle, which had already been linked to Stedman, KRTV reported. When Foiles, who was wanted for questioning about Stedman’s disappearance, came out of the motorhome, they approached him.

“I am Chris Foiles,” he allegedly told them, according to an affidavit. “I killed my girlfriend, she is in the RV.”

Officers searched the motorhome and found a woman’s body, with credit cards bearing Stedman’s name and a tattoo that matched the missing woman’s.

Foiles reportedly waived his Miranda rights and told detectives the body in the motorhome was Stedman. He said he and Stedman arrived in Idaho Falls around December 22 and parked at a Walmart, the arrest reporte said.

Foiles reportedly told the officers that he stabbed Stedman in the neck during an argument and “intentionally stabbed Megan in the chest with the intent to killer her.” He said later he could hear her still moving around in the back of the motorhome, so he went back and stabbed her until she stopped moving.

Foiles was charged with first degree murder and appeared in court on Tuesday.