Parents Seek Answers in Teen's Fatal Police Shooting in Hardee's Lot

— -- The grieving parents of Zachary Hammond, an unarmed teen fatally shot by police in South Carolina in July as he reportedly ate ice cream during a date, said today they just want to know what happened that night.

Hammond, 19, was in the parking lot of a Hardee's in Arden, South Carolina, when he was shot around 8:20 p.m. on July 26, according to The Associated Press.

Previous news reports said that Hammond and a woman were on a first date and eating ice cream on the night of the shooting.

Police, who had been running a drug sting in the parking lot, say Hammond had driven the 23-year-old woman to the parking lot to buy marijuana from an undercover cop, the AP said.

"This was over a little bit of marijuana. You don't kill people for marijuana," said Hammond's mother, Angie Hammond, today. "They make mistakes but, you can't just kill them for it. ... I would like the officer charged with murder."

A police lieutenant said he shot Zachary Hammond because he felt threatened as the teen drove up, the AP said.

An autopsy commissioned by the family shows that Zachary Hammond was shot twice –- to the back of his shoulder and his side. The Hammonds said that they believed there was a dashcam video and that they would like to be released.

Lawyers for the lieutenant -- Officer Mark Tiller -- said that he felt threatened when they say Hammond tried to crash into the officer with his car.

"If not for [his] quick reflexes and his ability to push off of the car, Lt. Tiller would have easily been run over by Mr. Hammond," the lawyers said in a statement. The officer and teen are both white, according to the AP.

Officials said Wednesday that the federal government was opening a civil rights probe into Zachary Hammond's slaying.

"This investigation will run parallel to the state's investigation," the Department of Justice said in a statement. "Because this is an ongoing matter, we are not able to comment further at this time."

Police would not comment on the case to ABC News tonight.