Walker's notes to medical staff indicated "he does not want to be resuscitated and expressed remorse for what had happened," Unified police wrote in the search warrant, seeking access to the Volvo that Walker was allegedly driving on Sept. 1, when he allegedly gunned down Draper police Sgt. Derek Johnson.
Police said they wanted to search Walker's car, which was so loaded down with belongings that only two people Walker and his girlfriend, Traci Vaillancourt could fit inside.
Police were seeking the couple's cell phones and evidence related to an earlier crash where Walker allegedly drove over a fence and a stop sign, which caused the car to break down, precipitating the deadly encounter.
Walker allegedly opened fire with a 9 mm Glock pistol when Johnson pulled up about 5:55 a.m. to check on the disabled Volvo near 13200 S. Fort St., according to the search warrant.
An autopsy determined that even though Johnson was wearing body armor, a single gunshot wound entered the officer's body just below his arm pit and just above the bullet proof vest and travelled through several organs, including his lungs, liver and heart, according to the warrant. A rib on the left side of Johnson's chest broke when it stopped the bullet.
Johnson called for help as he tried to drive away in his marked Ford Explorer, but crashed a short distance away, near 13000 S. Fort St. As Johnson fled, Walker allegedly fired three more shots at the departing police vehicle.
Another Draper police sergeant found Johnson inside the crashed vehicle, breathing, but unresponsive. The sergeant and medical crews started life-saving treatments, but Johnson died of his injuries.
Vaillancourt, 34, who also was allegedly shot by Walker during the episode, also wrote letters, but hers were to Unified police detectives. Police said a bullet entered Vaillancourt's right shoulder and lodged in the center of her chest.
Vaillancourt's notes allegedly told police that she did not know who shot her and that she was shot while inside of the Volvo. Police dispute this, saying the only blood found was on the exterior of the vehicle, according to the search warrant. Vaillancourt also allegedly wrote to police that she knew Walker had a gun and that he was the only person with her that day.
Vaillancourt has been charged with two counts of obstructing justice, both second-degree felonies, for allegedly giving police inaccurate accounts of the events.
Walker has been charged with aggravated murder and attempted homicide, both first-degree felonies, three counts of felony discharge of a firearm, and possession of a firearm by a restricted person, all third-degree felonies.
Prosecutors have not said whether they intend to seek the death penalty against Walker.
Walker is scheduled to make his initial appearance on Oct. 8 before Judge Mark Kouris, while Vaillancourt has a scheduling hearing the same day.