A father has been arrested after forcing his twin autistic daughters to stay inside a squalid, stifling RV, where one of them died, police said.

Roger Killam, 52, has been charged with one count of neglect resulting in the death of daughter Tamara, 25, and one count of neglect resulting in substantial bodily harm to her sister Brooke.

Read: Panicked Dad Puts Baby in Refrigerator After Pulling Her From Hot Car

Both were left for days in a trailer that had no working toilet and no running water , parked outside the Tropicana Express Hotel in Laughlin, Nevada, police said. Temperatures soared past 100 degrees.

The RV had no air conditioning and no power, according to Killam’s arrest report filed by the Las Vegas Metropolitan Police Department.

Officers were summoned last week to the trailer, where Tamara's father was performing CPR, the document said. But the young woman was dead on the floor, police said.

Brooke told investigators that she and her sister were being punished for going through the belongings of Killam’s girlfriend, Shannen Oulicky, the arrest report said.

The women were given only bread and water for the past week, she said. Brooke “appeared to be of diminished mental capacity” and couldn’t grasp the fact that her sister was dead, the document said.

Killam said he Oulicky had spent one night at a nearby motel in an air-conditioned room so the couple could have some “private time,” police said.

Read: Mom Leaves 9-Month-Old Daughter In Hot Car During Her Stripped Audition: Cops

Investigators later learned from motel receipts that the two had spent three nights in their room, leaving the twins to sleep in the RV, the report said.

Officers noted that both sisters were “filthy” and appeared to have not bathed in weeks. Brooke was taken to a nearby hospital for treatment of severe dehydration, police said.

The temperature inside the RV was 108 degrees, the document said. The trailer contained a 5-gallon bucket half-filled with human feces, according to police.

Killam was arrested on June 23. Officers said he “willfully caused his daughters to suffer unjustifiable physical pain (and) mental suffering resulting in the death of Tamara Killam.”

He “accommodated his own personal needs in renting a room with running water, climate controlled air conditioned room, clean bedding and ate a hot meal, all while his adult autistic twin daughters were left to fend for themselves in uninhabitable living conditions,” the arrest report concluded.

Killam, who is a transient, is being held without bail, police said. It was not clear whether he has an an attorney.

Watch: See This Man Use A Rock To Smash A Car Window To Save Dog In Hot Car