MANDAN, N.D. (AP) – Police in North Dakota say they’ve arrested a 44-year-old man in the killing of four people earlier this week at a business in Mandan.

Mandan Police Chief Jason Ziegler says surveillance video identified a vehicle of interest and helped lead them to the suspect, who lived in the small town of Washburn about 35 miles north of Mandan.

Ziegler also revealed for the first time that the victims had been stabbed or shot.

Ziegler says a motive for the killings isn’t yet known. He says the suspect lived in a trailer park managed by the business, RJR Maintenance and Management.

Ziegler says the man is being held on four counts of felony murder.