officer evans down an incline and then on the dash cam cane's son joe appears with a gun. >> bill is stumbling down this incline. he shoots at him. he didn't have time to get his weapon out. he hit him many times in the body, in the back. >> at that point, the second officer tries to help evans buth the 16-year-old turning his weapon on him. >> officer down, officer down. 277 westbound. >> a delivery driver witnesses the whole scene. >> these guys just shot a police officer. >> through the statements of the driver, this kid was very methodical, very slow, knew exactly what he was doing, and he handled that ak-47 like a military person would. >> the father/son team calmly gets back in the van and takes off leaving the officers bleeding on the ground. >> shortly after more police arrive and find that officer evans is alive but just barely. >> and there was about three