BISMARCK, ND (KXNET) — New details regarding the early October murder of Christopher Sebastian, allegedly by Benjamin Williams, in the parking lot of the 200 block of East Arbor Ave in Bismarck have been revealed in the official affidavit released by police.

According to the affidavit, when officers arrived on the scene around 11:30 p.m. on Oct. 4, they were told by witnesses they had heard a gunshot, (or multiple gunshots according to one witness), and then saw a man running away from Sebastian’s vehicle.

One witness shared a video with officers they took that showed a person running westbound on the south side of the Bismarck Hotel. That led officers to find a black-hooded sweatshirt and a Glock 27 handgun, (which had blood on it), in the bushes on the west side of the hotel.

Upon investigation of the vehicle, officers noted Sebastian had what appeared to be a fatal gunshot wound to his head. Inside the vehicle, they also found .40 caliber spent cartridge casings, bullet jacketing material, .40 S&W ammunition, blood/body tissue, and two Glock magazines, both containing unfired .40 ammunition. Additionally, a bag containing more unfired .40 ammunition was found in a backpack on the passenger side floor.

Police then investigated video surveillance from around the same time as the shooting that allegedly showed Williams talking on a cell phone on South 2nd Street, directly across from the Bismarck Hotel.

The following day, law enforcement responded to a call at a residence in Bismarck regarding a reported overdose around 1:20 a.m. on Oct. 5. The subject of the call, officers would learn, was Benjamin Williams.

According to the Bismarck police, the owner of the residence, (the affidavit states only that their initials are T.W. and they are 50 years old), provided video surveillance of Williams arriving at their home with no shirt, no shoes, and his pants inside out. T.W. then told law enforcement that they put Williams in the shower as he was overdosing. He was then taken to the hospital by ambulance and then returned home by T.W.

Due to his use of drugs, Williams violated the parole he was serving following his release from prison earlier this year after he pled guilty to aggravated assault and tampering with physical evidence in 2017. In earlier reports, police said he was taken to the Burleigh Morton Detention Center.

Law enforcement then conducted an interview with Williams the following day where a gunshot residue testing kit was used on both of his hands. Both allegedly came back positive for gunshot residue.

During the interview, Williams admitted to being with Sebastian on Oct. 4 from 7 p.m. to 10 p.m. Williams stated that Sebastian dropped him off on “North Washington” at 10 p.m. During that time, the two apparently drove to the North Bismarck Walmart and the Mandan Walmart.

Williams also stated that Sebastian was “acting weird” and that he was “talking differently.”

Upon investigation of video surveillance of the North Bismarck Walmart, police found video of Williams apparently entering a vehicle in the parking lot at 11 p.m. with Sebastian. Williams was reportedly seen wearing a black hooded sweatshirt, similar to the one found in the bushes at the Bismarck Hotel.

Based on the investigation, Williams was then charged with Murder-Intentional, knowing, or with extreme indifference and Unlawful Possession of a Firearm.

Williams is currently being held in the North Dakota State Penitentiary with a trial scheduled to begin on February 21.