Tremaine Wilbourn had been wanted for the shooting death of police officer Sean Bolton on Saturday night.
After his arrest on Monday, Wilborn told police that " I'm not a cold-blooded killer", and "I am not a coward".
Memphis Police Director Toney Armstrong had shown a photo of Wilbourn earlier that day and labelled him a "coward".
Bolton was investigating an illegally parked car where a drug deal was taking place, Mr Armstrong said, when the shooting occurred.
A struggle took place, which ended with Wilbourn drawing a gun and firing on the officer who later died in hospital.
Police discovered less than two grams of marijuana at the scene.
In announcing the surrender, Mr Armstrong credited the "exhaustive search" for raising public awareness and putting pressure on Wilbourn.
"We've always been one step behind him, but he felt the walls closing in and thought it was in his best interest to turn himself in," Mr Armstrong said.
Wilbourn, 29, had an earlier conviction for bank robbery. He had been sentenced to more than 10 years in prison and was released on probation in July 2014.
Bolton, 33, had served as a US Marine in Iraq.
Wilbourn's first court appearance is scheduled for Wednesday.
A man suspected of killing a Tennessee police officer has turned himself in to authorities, ending a two-day manhunt.