UPDATE (9:55 p.m.): Around 8:30 p.m, a large police presence arrived at Chad Isaak's house at the Northview RV Park in Washburn and began going inside.

Isaak's next door neighbor, Dale Ronholdt, says he was in the neighborhood during the arrest. Ronholdt says the police were prepared with many officers. When he saw that amount of law enforcement gathered, he says RJR was the first thing that came to his mind.

Ronholdt says Isaak is a fairly well-known chiropractor in Washburn.

He says he'd watch Isaak's dog from time to time, and never heard the him complain about RJR.

We do know that the management company took over running the Northview RV Park park just last summer.

UPDATE (9:18 p.m.): Mandan Police Chief Jason Ziegler said in a news conference Thursday they have made an arrest in the quadruple homicide at RJR Maintenance and Management.

He says 44-year-old Chad Isaak of Washburn has been arrested on four counts of AA felony murder.

Police responded to RJR Maintenance and Management in Mandan on April 1 for a medical call where officers found four victims deceased. They say the victims had suffered gunshot and/or stab wounds.

Video surveillance led to investigators identifying the suspect vehicle and the McLean County Sheriff's Office located the vehicle in Washburn.

During a traffic stop on the suspect vehicle, a search warrant was executed where evidence in the vehicle, and on Isaak, gave authorities probable cause to place him under arrest for the murders.

Police say the motive is unknown and the investigation is still ongoing.

Isaak owns Isaak Chiropractic of Washburn.

He is being held at the McLean County Jail.

UPDATE (8:00 p.m.): McLean County Sheriff JR Kerzmann confirmed a man was detained in front of Captain's Cabin on the road.

It happened just after 3:30 p.m. Thursday. He says it was a traffic stop by McLean County Sheriff's Office and the man was in a white truck.

Kerzmann says 20 deputies were sent to the traffic stop.

He also says the man was taken off on a public street away from residences. Deputies say no one was at risk and the safety of residents and law enforcement were a priority.

Law enforcement is holding a press conference at 9:00 p.m. Thursday, April 4 from the Mandan City Hall.

ORIGINAL STORY (6:21 p.m.): The Mandan Police Department says they have detained a person of interest in Washburn in relation to the Mandan murders on Monday.

MPD, the North Dakota Bureau of Criminal Investigation and the McLean County Sheriff’s Office were following a lead that led investigators to Washburn.

MPD is continuing to update us on this information.

UPDATE: New details on Mandan murders #UPDATE: New details regarding the quadruple homicide that took place at RJR Maintenance and Management earlier this week. Posted by KFYR-TV on Thursday, April 4, 2019

Police vehicles arrive at the house of a suspect taken into custody for the murders at RJR Maintenance and Management. Posted by KFYR-TV on Thursday, April 4, 2019