UPDATE: The alleged gunman who shot and killed a Memphis police officer during a traffic stop turned himself in late Monday, ending a two-day manhunt, officials said.

Read the original story below.

A full-scale manhunt is on in Memphis, Tennessee, after a police officer was shot and killed during a traffic stop. 

Police are searching for Tremaine Wilbourn, 29, (pictured above), saying he had been on supervised release following a bank robbery conviction. 

Officer Sean Bolton, 33, (pictured below) a Marine who served in Iraq, came upon an illegally-parked vehicle in which police believe Wilbourn was the passenger.

Bolton illuminated the Mercedes-Benz with a spotlight and was then confronted by Wilbourn, who allegedly shot Bolton during the ensuing struggle. 

Police suspect that Wilbourn was participating in a drug deal in the car when Bolton arrived. Less than two grams of pot was discovered in the vehicle. 

"He's a coward. You murdered a police officer for less than 2 grams of marijuana. You literally destroyed a family," Police Director Toney Armstrong said of Wilbourn. 

Wilbourn was reportedly sentenced to 121 months in prison this year for a bank robbery, but was released on July 7 after paying a fine and agreeing to mental health treatment.

Police say a civilian used Bolton's radio to call for help, but the officer succumbed to his wounds at the hospital.

You can hear the audio below in Jonathan Serrie's report.