"All I could tell my kids was to get down," the witness told ABC15.
This man, who asked to remain anonymous, said he saw an officer pull up behind an SUV at 35th Avenue and Camelback Road in Phoenix without a siren or flashing lights.
"I saw him run out with the gun and I had my family in the car, so I just stopped right there in the middle of the road," he said.
He watched what would eventually become a crime scene start to unfold Sunday night. The witness says the officer started screaming at the SUV's driver.
"He got out of his car with an assault rifle in his hand, pointed it at the car. It was unbelievable because it was literally within 10 seconds that shots were fired.
So there's no possible way this kid had a chance to surrender," he said.
But that's where his story differs from the police report. Phoenix police told us the officer initially pulled over the driver because the car was reported stolen.
Then, according to police, the driver, who was just 15 years old, "revved the vehicle's engine before putting it into gear, telling his passenger, he was going to 'slam it'. The vehicle drove at the officer, who fired one time."
"The driver did not try to run over the officer, that's what I want to make clear. Shots were fired first and then the car moved slowly, so like 4-5 miles per hour. So I'm guessing the car was on drive, the brakes weren't on and that's when someone made a sharp turn to the right and the car crashed into the house," he said.
Police said they interviewed three people who were at the scene. This witness said he plans to tell police his side of the story because the 15 year old's family deserves to know what he said happened.