This is an archived article and the information in the article may be outdated. Please look at the time stamp on the story to see when it was last updated.

MEMPHIS, Tenn. — An ex-convict facing federal charges in the fatal shooting of a Memphis police officer has changed his plea to guilty to federal charges.

Tremaine Wilbourn had pleaded not guilty to charges filed in connection to the December 2015 in the killing of Officer Sean Bolton.

Bolton was shot and killed as he approached Wilbourn’s car August 1, 2015 in the 4800 block of Summerlane Ave.

Investigators say Wilbourn ran and carjacked a man at gunpoint.

Two days later, Wibourn turned himself in and was identified by the carjacking victim.

Federal prosecutors charged Wilbourn with carjacking, possessing a firearm during and in relation to the carjacking, and felony possession of ammunition.

Wilbourn pleaded guilty to all three charges.

According to an indictment, Wilbourn used a gun while carjacking a man on the same day of the officer’s shooting.

Wilbourn still faces first-degree-murder and other charges in state court.

WREG spoke with Wilbourn’s emotional grandmother Friday afternoon who said she is glad her grandson is owning up to some of his charges and she’s heartbroken for everyone involved.

“It got out of hand. And it’s just a tragedy. On both sides, no matter which way you go both us lost,” said Sandra Richardson.

Wilbourn’s next court date is May 23.