Prosecutors filed a deliberate homicide charge against Zackary Matthew Maas on Friday after the man he allegedly shot in March succumbed to his injuries in King County, Washington.

The 25-year-old Columbia Falls man previously faced an assault with a weapon charge in Flathead County District Court stemming from the March 13 shooting in Kalispell. In a newly-filed affidavit, prosecutors wrote that the victim died on Thursday morning of "homicide due to complications of subacute gunshot wound to the back."

A King County medical examiner made the determination.

Authorities began investigating Maas after responding to a shooting on the 700 block of First Avenue West of Kalispell about 4:33 a.m. Kalispell Police officers found the victim face down atop a stairwell inside his home, suffering from a gunshot wound to his back, court documents said.

The victim allegedly fingered Maas and another man, Jerum Auclaire, in the attack. According to court documents, the two arrived at his home, with Maas immediately putting a gun to the victim’s head. Auclaire then put the victim in a chokehold while Maas allegedly began punching him and striking him with the gun, documents state.

After the alleged beating, the victim opened the door for the two men to leave. As they exited, Maas shot the victim in the back, court documents said.

The duo fled in Auclaire's GMC pickup and prosecutors accused Maas of trying to hide the firearm in Auclaire's vehicle.

Meanwhile, the victim was taken to Logan Health and later Harborview Medical Center in Seattle for medical treatment.

Authorities caught up with Maas on March 14 following a traffic stop. According to court documents, he admitted shooting the victim.

Maas was released from the Flathead County Detention Center in March after posting a $100,000 bond. He pleaded not guilty to assault with a weapon on March 31. An arrest warrant issued April 15 put his bond at $300,000. The county jail's website does not currently list Maas as an inmate.

Auclaire faces an accountability to assault with a weapon charge in district court. He pleaded not guilty to that charge on March 31. No new charges had been filed against him as of April 15.

News Editor Derrick Perkins can be reached at 758-4430 or [email protected].