In his 17-minute videotaped statement to police, Quintero appeared calm as he recounted his version of what happened the night Johnson pulled him over for speeding.
"I asked him if he was going to give me a ticket for speeding," said Quintero on the tape. "He said, no, he's gonna take me with him, and right after that, he put the handcuffs on me."
Officer Johnson arrested Quintero for not having a driver's license and placed him in the back seat of his squad car. Unaware that Quintero had a pistol in his waistband that was overlooked during a search, Johnson radioed for a wrecker from the front seat of his patrol car.
"Uh, send me a wrecker, Braniff at Randolph, Braniff and Randolph," said Officer Johnson in a recording from just moments before he was gunned down.
Sgt. David Ferguson was heard on the tape saying to Quintero, "He gets back in the patrol car and calls for a city wrecker. Had he already put the radio down, I mean the microphone down."
Quintero: " Yes."
Ferguson: "Is that when you shot?"
Quintero then demonstrated for police how he managed to maneuver the hidden weapon his waistband.
Ferguson: "Your hands are behind you, so you're handcuffed. What did you do?"
Quintero: "I cocked it with the other hand, reached over my foot and got to the window."
The sliding window was partially open. Quintero opened fire. Officer Johnson was shot four times in the back of the head.
Ferguson: "How many times do you think you shot?"
Quintero: "Seven, I guess."
Ferguson: "It was fully loaded."
Quintero: "I think it had eight rounds."
Ferguson: "Why were you carrying a gun?"
Quintero: "It's not safe anywhere you go. You get robbed everywhere and the cops are not there when you need it."
Quintero is pleading not guilty by reason of insanity. Defense attorneys claim he's mentally ill and that brain damage caused him to perceive a threat that wasn't there. Prosecutors are seeking the death penalty.