MOUNTAIN GATE, Calif. -

A man is dead after deputies say he was shot in self-defense.

The Shasta County Sheriff's Office swarmed the Spring Branch Mobile Home Park on Tunnel Road after the shooting was reported a little after 4:30 p.m.

Investigators said when they arrived on scene they found a man with a single gunshot wound to the upper torso in the road.

He was taken to a hospital where he died.

His name is not being released pending notification of next of kin.

At the mobile home park deputies contacted 32-year-old Matthew Robinson.

Robinson told investigators he had recently started a relationship with the victim's ex-girlfriend, Amanda Rizer.

The victim and Rizer share a child and today was the child's first birthday.

When the victim showed up at the house he became enraged Robinson was there.

There was an argument and the victim eventually left.

About 20 minutes later he called Rizer and said he was coming back to take the child.

When he returned he got into another argument with Robinson.

Rizer and Robinson told deputies the victim had a tendency to be violent and is usually armed so Robinson armed himself with a .38 caliber handgun in case he felt threatened. 

During the argument Robinson showed the handgun and told the victim to leave.

Deputies said the victim advanced on him so Robinson fired a warning shot.

The victim then told Robinson he had a gun in his truck and went to retrieve it.

Robinson told deputies Rizer's ex then pulled a 9mm handgun from the truck and pointed it at Robinson.

Robinson, fearing for his safety, fired a single shot, hitting the man.

After an investigation, detectives learned the victim's pistol was actually a toy that looked like a real handgun. There was no orange safety paint on it.

Investigators said it appears Robinson acted in self-defense.

He was questioned and eventually released pending a review of the case by the Shasta County District Attorney's Office.

Detectives said the victim and Robinson have a lengthy criminal history.