A Washington state man is accused of killing his pregnant ex-girlfriend after a body was found on a hillside, officials said.

Colin Patrick Dudley, 37, of Tacoma, appeared in court Wednesday for the murder of 33-year-old Kassanndra Cantrell, who was three months along when she vanished on Aug. 25, news station KOMO reported.

Relatives reported Cantrell missing after she hadn’t been heard from for two days and failed to arrive at a doctor’s appointment, according to the Tacoma County Sheriff’s Office.

“Her disappearance was out of character and was very concerning for her loved ones,” authorities said.

The day after she was reported missing, her white Mazda 3 sedan was discovered abandoned without any trace of the missing woman, authorities said.

On Sept. 1, authorities carried out a search warrant on Dudley’s home and confiscated several items, including his truck.

Using GPS data obtained from the truck, they zeroed in on a wooded area in University Place, about 10 miles from Dudley’s house, authorities said.

Detectives on Tuesday uncovered wrapped human remains that had been dumped on a steep hillside near Chambers Creek.

The remains are believed to belong to Cantrell, pending official confirmation from the medical examiner’s office, officials said.

“It’s so devastating to everybody. We’re all, we’re all just in shock,” Kassandra’s aunt, Stephanie Cantrell told KOMO News.

She said the family believes Dudley was the father of her niece’s unborn child.

“This is the coward way out, this is a horrible, horrible way out… it’s sickening,” Cantrell.

Dudley was arrested at his residence Tuesday and booked at Pierce County Jail, where he’s being held on a first-degree murder charge, officials said. He’s expected to return to court Friday.