Authorities investigating Sunday's fatal shooting of Shreveport police Sgt. Tim Prunty believe they know what happened that night. What they don't know is why. Almost unanimously, investigators said the shooting makes no sense.

On Monday, the day after Prunty was killed outside a southside convenience store in an apparently random attack on a police officer, investigators continued looking into the life of his accused killer, 24-year-old Christopher Cope of Shreveport.

Cope is accused of driving up to a convenience store at Bert Kouns and Dean Road early Sunday and -- without saying a word -- opening fire on Prunty, a patrol sergeant who was on duty and was talking to the store clerk outside the store.

Investigators said there was no record of any contact between Prunty and Cope and the officer apparently was picked at random. Prunty was shot several times, including as he lay on the ground, police said in a court document filed Monday. The officer returned fire but did not hit his attacker. The store clerk was not hurt.

Detectives are retracing Cope's actions that night.

They have been talking to the young woman he had been with.

They've also talked to his parents. His father, Karl, is a retired Shreveport police captain described as a quiet, solid officer to whom the police department was very important. A friend of the Cope family described them as devastated and stunned by what has happened. Authorities said Cope had been living at home.

Authorities said Cope told detectives his life had gone sour, he was depressed and wanted to end it -- so he found a police officer at random and shot him, an act that could draw the wrath of law enforcement.

But Cope's actions after shooting Prunty contradict that. When police spotted his car and pulled him over, police said, he held the gun out the window, unloaded it, dropped it and got out of the car. Patrol officers tackled him and arrested him.

An hour before Prunty was shot, police said, Cope drove by and fired a shot at the security gatehouse outside Southern Trace neighborhood in far southeast Shreveport. The security officer was not hurt.

Cope, who is jailed without bond, made his initial court appearance Monday. He told Caddo District Judge Mike Pitman he had a job that didn't pay much and could not afford a lawyer. The public defender was appointed to represent him and he will be arraigned Dec. 6, the week after the Caddo Parish grand jury hears his case.

The district attorney's office is making preparations to seek a death sentence.