GRAND RAPIDS, Mich. (WOOD) — The fire that killed a mother and her three children in Grand Rapids earlier this year was started in a burn pit by the suspect, police told a judge in court records obtained by News 8.

Robert Scales, 38, has been charged with four counts of involuntary manslaughter in the fire that killed his wife and three children.

Xavier Woldeab, 15, Elijah Scales, 10, and Robert Scales, Jr., 14, and their mother Wanedia Scales, 35, were identified as the victims.

In an affidavit of probable cause to arrest Robert Scales, police told a judge details about how the fire started.

The officer wrote that Robert Scales admitted to starting a fire in a pit outside of his home the evening before the home caught fire and letting the fire go out on its own before leaving for work, according to the affidavit.

The fire pit was located about six feet from the home and fire investigators determined it was the origin of the fatal fire at the home, the affidavit states. There was a mattress located between the fire pit and the home.

A friend of Robert Scales was interviewed by police and said he was with scales as he used starter logs to initiate the fire and burn leaves. He said there was no mattress near the pit when he was there, the affidavit states.

“He stated that he told Robert he needed to get a bigger pit and move it away from the house,” the affidavit reads.

The document reports that there were no working smoke detectors in the home at the time of the fire.

A judge found that there was probable cause to arrest Robert Scales and he turned himself in last week.

Family members of the victims say the involuntary manslaughter charges don’t go far enough.

They believe Robert Scales set the fire intentionally. Waneida Scales had filed a petition for a personal protection order stating that her husband had threatened to burn their house down with her and the kids inside.