Washoe County investigators ruled Dale Mattson's death a homicide after numerous gunshot wounds to his head, torso and other extremities made it difficult to determine which was the fatal shot.

Police say they found the 43-year-old Sun Valley man, whom they skirmished with off and on in a nearly 40-hour standoff dead in his home Monday on the 300 block of Gepford Pkwy in the Northern Washoe County neighborhood.

Mattson had been unresponsive since a gun battle between Washoe County Sheriffs and him took place before 8 a.m. after officers attempted to coax him out with a loudspeaker and tear gas according to News 4 crew on the scene.

The incident began Sun., Nov. 9 around 5 a.m., when sheriff's deputies were serving a felony warrant on Mattson, a fight broke out and the Sun Valley man pulled a handgun.

Washoe County Spokeswoman Brooke Keast said officers were able to get the gun after tasing the suspect but Mattson ran into a home, grabbed a shotgun and fired a round at a sergeant.

No one was hurt, but deputies retreated from the house, set up a perimeter and called for backup.

According to police on scene SWAT officers, bomb-trained personnel, seven hostage negotiators and Washoe County deputies, the Sparks Police Department and the FBI were handling the situation.

On Sunday, law enforcement sent in a robot capable of sending back live video from inside the house, and picking up weapons.

"At this time, he's had no communication with us, despite our efforts," said Asst. Sheriff Marshall Emerson on Sunday.

Late on Sunday afternoon, authorities tossed in several flash-bang devices and tear gas in an effort to bring Mattson out.

Mattson responded with shots from what officers believed to be an AK-47-like weapon.

By nightfall, law enforcement used larger and louder devices, but Mattson refused to come out.

As Washoe County negotiators and SWAT team members stood down after 12 hours on the job, Sparks police took over.

Everyone involved said they only wanted the situation to end peacefully.