US cop escapes charges for shooting dead unarmed teen

A US policeman will not face charges after shooting to death an unarmed teenager as he attempted to drive away from him.

Mark Tiller, from Seneca, South Carolina, shot 19-year-old Zachary Hammond in late July during an attempted drug sting, the New York Daily News reports.

WARNING: Users may find the above video upsetting

Mr Hammond was on a first date with Tori Morton, 23, and had gone to get a hamburger when an undercover policeman attempted a drug deal with Ms Morton.

In dashcam footage, which Seneca police had tried to stop being released, Tiller can be seen approaching Mr Hammond's car with his gun drawn, demanding they put their hands up.

When Mr Hammond tries to drive away, Tiller shoots him twice.

"He tried to hit me!" he yells.

Ms Morton was later charged with simple possession of marijuana.

Mr Hammond's parents, Angie and Paul Hammond, said they were dismayed at the result of the investigation and would pursue a lawsuit.

"There are a lot of questions and very sorry police work, very sorry police work," Paul Hammond said. "My son lost his life and he should not have."

In the lawsuit, the Hammond family claim their son's body lay for 90 minutes on the ground and was bitten by ants.

Another officer gave the teen's lifeless body a high-five, the lawsuit alleges.