The attorney, David Winslow, said the officer was getting a food sample for his son when he was attacked and briefly knocked out.
"He was shopping with his wife and 1½-year-old at Costco. His son was was in his arms and he was feeding his son some samples when within seconds he was on the ground and woke up from being unconscious and he was fighting for his life," Winslow said in an interview with The Times.
Authorities said the assault, which was captured on Costco security cameras, was unprovoked and led the officer to fire his weapon, killing Kenneth French, 32, and wounding two of French's family members, whom a relative identified as French's parents.
The officer did not know of the man's disability at the time, according to a law enforcement source who spoke on the condition of anonymity.
French lived with his parents and had the mental capacity of a teenager, his cousin Rick Shureih said in a phone interview.
"He was a gentle giant," Shureih said. "He's never been violent in the past.
Well, he wasnt "gentle" in this instance. I dont care who you are, you assault me with my kid, you are going to die.
Apparently, this was caught on camera and several witnesses corroborate what the police said happened to him.