Carnan was shot dead after trying to flee authorities on a tractor. He had allegedly just killed a woman believed to be his mother, though she has yet to be identified.
Police said they received a 911 call from Carnan's brother about his mother's possible murder on Saturday afternoon. They arrived to find the house on fire and a dead woman's body inside.
While officers were still at the deceased woman's home, they began receiving reports of a man firing shots around Simi Valley's Bridal Path neighborhood.
“Guy come by with a tractor. Got my dog there and he comes by and I said, ‘Are you shooting up there?’ And then he looks at me with the gun. He has the gun. And I said, ‘Oh, you are shooting up there’ and he just stared at me,” a witness told CBS Los Angeles.
Nearby homes were evacuated and searched as police pursued Carnan and returned fire. Carnan died during the exchange.
“Police have to make quick decisions. That decision in this case resulted in an individual being shot by our officers that what I would suggest has been the direct result of saving people’s lives in this neighborhood,” Cmdr. Stephanie Shannon, of the Simi Valley Police Department, said in a statement.
One neighbor told the Los Angeles Daily News that Carnan's brother was “completely distraught," over the incident.
"He was in tears, he was shaking,” Dave Phillips said. “I spent 10 or 15 minutes with him over the next hour, as did [another neighbor] just trying to console him.”