A drug dealer was found guilty Wednesday of fatally a shooting a man who tried to step in while a mutual acquaintance was being harassed, the Fulton County District Attorney's Office announced Thursday.

Didrekeus Lewis, 32, was convicted by a jury of murder, felony murder, aggravated assault and battery, and weapons charges in the death of 47-year-old Marvin Printup. He was sentenced to life plus five years in prison.

Authorities said Printup was shot in the stomach on Sept. 11, 2010 and died six months later as a result of his injuries.

Printup and a female acquaintance went to the Citgo gas station at Martin Luther King Jr. Drive and Fulton Industrial Boulevard in Atlanta to pick up Paul Sadeghy, the DA's office said.

Sadeghy had called for a ride because Lewis, from whom he had purchased drugs before, was harassing him for money and following him around the store, authorities said.

Printup, who knew both men, urged Lewis to calm down as the group left the store. Authorities said Lewis got angry, pulled out a gun and fired two shots at Printup at point-blank range, then two more as Printup tried to run away.