No charges will be filed against a Tennessee police officer who fatally shot a man suspected of wounding two people, a prosecutor said Tuesday.

A Memphis Police Department lieutenant was acting in self-defense when the officer killed Terrance Deshun Carlton, 25, in April 2018, Shelby County District Attorney Amy Weirich said.

Officers saw Carlton walking in the area where two people were shot and wounded during a robbery, Weirich said in a statement. Police said the officer ordered Carlton to stop. Carlton tried to run away but stumbled.

Police said Carlton had something dark in his hand as he rolled over and shouted, "I'm going to kill you."

The officer, who was not identified, fired twice, hitting Carlton.

A cellphone and a gun were found nearby.

"(The officer) was in uniform and in the act of lawfully apprehending a suspect wanted in two nearby shootings that occurred a short time earlier," Weirich said in a letter to Memphis Police Director Michael Rallings. "The suspect's threats and actions gave the lieutenant abundant reason to fear for his life and to act with lethal force in self-defense."

Carlton died at a hospital. Two bullets were recovered from his body from old gunshot wounds, investigators said. Carlton had drugs including methamphetamine and oxycodone in his system, Weirich's statement said.

Weirich reviewed a report by the Tennessee Bureau of Investigation on the shooting. An examination by TBI showed the gun found in the area of Carlton's shooting matched cartridge casings recovered from the shootings of the two people.

Carlton's DNA also was found on the weapon's magazine, the district attorney said. One of the wounded people knew Carlton by name and the other later identified him in a photo spread, she said.

Carlton's shooting was recorded by the officer's body camera and a business's surveillance camera.

Carlton's mother is suing the police department over the shooting. Marlene Alexander said in the lawsuit that her son was unarmed when he was shot.