Jesse Mathews pleaded guilty on Friday afternoon to killing Chattanooga Police Sgt. Tim Chapin.
He was sentenced to life in prison without the possibility of parole after pleading guilty to six different charges - first-degree murder, felony murder, three counts of attempted first-degree murder and aggravated robbery. He received an additional 25 years beyond the life sentence.
The state had been seeking the death penalty against him.
Mathews gave up all of his appeal rights.
Judge Barry Steelman asked Mathews if he understood that the pleas meant "life in prison without parole." Mathews said, "I understand."
Judge Steelman had been planning to try the case here starting on Jan. 23 using a Nashville jury.
Sgt. Chapin was shot and killed near a pawn shop on Brainerd Road on April 4, 2011.
Prosecutors said members of the Chapin family went along with the plea deal.
Sgt. Chapin left behind a wife, son and daughter.
A large number of police officers were in the courtroom for the guilty plea, including Lorin Johnston, who was shot by Mathews during the same incident.
Mathews is a former Colorado parolee whose family had moved to Chattanooga after he skipped out of a halfway house and committed several new armed robberies.
The plea deal will end a lawsuit that defense attorneys Lee Davis and Bryan Hoss filed in Federal Court seeking to have prosecutor Steve Neff testify at the sentencing phase of the Mathews trial. Also in that case, the attorneys asked Federal Judge Sandy Mattice to testify.
Both prosecutor Neff and Judge Mattice declined to testify.
District Attorney Bill Cox and chief assistant Neal Pinkston handled the case for the state.
Police had arrived quickly on the scene of the holdup at the U.S. Money Shop near Big Lots. Sgt. Chapin was among those following Mathews on a narrow road nearby. Apparently, they exchanged shots and Mathews dropped the gun he was using. However, he then reached for a second gun that he had on him and he shot Sgt. Chapin in the forehead.
Mathews was captured a short distance away by a nearby resident, who forced him to kneel until police arrived.