Washoe County Sheriff’s Office officials announced that a Sun Valley man was found dead at about 4:30 Monday afternoon following an almost two-day standoff with local law enforcement and the FBI

Dale Herman Mattson, 45, began the lengthy standoff Sunday evening after Washoe County deputies attempted to serve him with a $250,000 federal warrant, claiming that Mattson allegedly made a bomb threat. Mattson also had an outstanding traffic citation.

A WCSO spokesperson said the last communication they had with Mattson was earlier Monday morning when he exchanged gunfire and threw a few expletives at deputies.

Officials did not confirm whether or not the bullet that killed Mattson was from suicide or the gunfire exchange.

When deputies arrived Sunday at about 6 a.m., Mattson grabbed a gun and opened fire.

Since then, multiple rounds of tear gas were fired into the residence and gunfire was exchanged. Sheriffs deputies also released a concussion grenade into the east side of the house at about 12:30 p.m. Monday.

According to Assistant Sheriff Marshall Emerson, several long guns were removed from the residence Sunday by the Washoe County Sheriff’s Office’s robot. Also, according to scanner chatter, Mattson was possibly equipped with a gas mask and chemical suit.

Several neighbors claimed that Mattson’s residence had been frequented by law enforcement recently, but county deputies would not confirm those reports.

Residents from about 10 homes in the surrounding area were asked to evacuate, WCSO officials said. However, some chose to stay in their homes. Mattson’s residence at 390 Gepford Parkway is mostly surrounded by a park and sports fields.

The WCSO, Reno and Sparks police departments, the Reno Fire Department, REMSA and the FBI were all on the scene since the standoff began. Washoe County Deputy Brooke Keast estimated that about 40 responders were on scene at any given time.

Emerson did confirm that Mattson was the owner of two wolves. One of the animals had run away Sunday night and animal control officials were still looking for it at press time Monday.

The other wolf was still at the residence with Mattson, Emerson said.

No law enforcement personnel had been injured as of Monday afternoon, Emerson added.