Dylan Noble died in June after police shot him four times, twice as he approached officers, twice while he was on the ground, still moving.
His family thinks Fresno police didn't need to use deadly force.
Police Chief Jerry Dyer said there are questions that body camera recordings, released Wednesday, answer and some they don't.
Was deadly force, in particular the final two shots -- taken by two different officers -- necessary?
"I do not have the answer for that today," Dyer told reporters in the central California city of 520,000 people.
An internal affairs investigation will look into whether police procedures were followed and whether there were other options. A review by the district attorney will determine whether the two Fresno police officers should be criminally charged.
"We're shocked and appalled that the city of Fresno would continue to defend the actions of its officers," said Stuart Chandler, an attorney for Veronica Noble, Dylan's mother. "Clearly the only appropriate response is to accept responsibility and commit to changing practices of the police department."
The chief said police originally responded to the area June 25 after a report of a man carrying a rifle while walking down the street. The two officers were riding together. One was a reserve officer.
They were stopped at a red light when a black pickup truck made a right turn onto the road in front of them and with screeching tires, appeared to speed away. The officers followed and after catching up to the truck, attempted to pull the vehicle over. The pickup driver kept going for another half mile.
The officer, Dyer said, began to suspect the driver was the man with a rifle call. He drew his handgun as he followed the pickup, just as it turned into a gas station and parked.
Both officers came out of the car with weapons drawn. Video shows Noble putting his left hand out the window. An officer yells at him to put both arms out.
During the next one minute, 17 seconds, Noble is in the vehicle but doesn't fully comply with officers' commands, the chief said. Officers get closer to the truck.
At one point, Noble climbs out of the pickup and an officer yells that he didn't tell Noble to get out of the vehicle. Noble gets back in the truck, leaving the door open. The officers move back to their car.
"Let me see your hands," an officer says repeatedly.
Noble gets out of the truck again and walks away from the officers, who tell him to get on the ground. He walks several more steps then turns around.
Dyer pointed out that at this point Noble has his right hand behind his back. He continues toward the officers then backs up. An officer yells for him to get down but instead he walks back toward the officers.
"What do you have in your hand?" one asks. Then he warns Noble he's going to get shot.
As Noble walks toward the officers, he hears another command to get on the ground. And Noble says, "I (expletive) hate my life."
The officer with a handgun, a veteran of 20 years, fires twice. Noble goes down and rolls onto his back.
Dyer said when he reaches for his waistband the officer fires again.
Noble squirms while he is told to not to move his hands. About 14 seconds later, the reserve officer, who has 17 years of service, fires once.
Noble didn't have a gun; he had what Dyer described as a piece of clear plastic, 4 inches by 4 inches, that contained moldable clay.
"We don't know what that is," Dyer said.
The chief said he viewed the video on Friday with Dylan Noble's father, stepfather and attorneys for the parents.
The father is "extremely disappointed at the way the police handled this shooting and he's relying on outside agencies for providing him with answers and justice," said Warren Paboojian, the lawyer for Darren Noble.
Paboojian said Dylan Noble would be alive if Fresno police had treated it like a normal traffic stop.
"You don't point (a weapon) at an individual for a traffic stop," he said.
The parents each plan to file a lawsuit against the city, but the actions likely will be combined into one trial, Chandler said.
