Mother of Arlington sniper says son was bipolar

Mother of Arlington sniper says son was bipolar »Play Video
ARLINGTON, Wash. -- The holiday weekend turned horrific for an Arlington neighborhood when a gunman opened fire.

Investigators are now working to solve several unanswered questions about the shooting while the gunman's mother struggles to understand why her son snapped.

Investigators believe the gunman, who has not been officially identified, acted alone when he shot a passerby in the leg and fired at police and SWAT officers in a rural area outside of Arlington Sunday.

Now a woman who claims to be the shooter's mother is speaking out about her 60-year-old son's mental health problems.

Kathleen Endrizzi of Mount Vernon was told her son, Robert, was the sniper. She said he had previously worked in the medical field, but retired after a terrible motorcycle accident.

"He was bi-polar and taking medications and that lead to conflicts sometimes," Endrizzi said.

Despite his mental health issues, Endrizzi said she doesn't know what sparked Sunday's violence. Robert reportedly moved to the neighborhood earlier this year and wasn't friendly with any neighbors.

Some neighbors say they've heard gunfire before, but no one had ever been targeted.

"We were pretty lucky," the victim's father said. "We were like sitting ducks out there just walking around."

The 26-year-old man who was shot in the calf at the beginning of the incident was taken to Cascade Hospital in Arlington, where he was treated and released.

An autopsy will determine if the gunman died from Suicide or an officer's bullet.