MARIETTA, Ga. -- Police in Marietta are investigating a robbery at a video game store that left the manager dead.

Authorities believe 21-year-old Matthew Cherry died from suffocation after his face was covered with duct tape during the robbery. The incident happened shortly after 6 p.m. Sunday night.

"I can't even begin to imagine what (Cherry) went through or what his co-worker and co-worker's father went through sitting there watching this go on," said police spokesman Mark Bishop.

Another store employee and his father were tied up during the robbery but were not hurt.

Bishop says the suspect left with video game consoles, video games and DVDs after spending about a hour and a half in the store.

Police also believe the suspect stole the victim's car. The car is described as a red, two-door 2004 Honda Civic LX with Georgia license plate 2010 ASW.

A $10,000 reward has been posted in the case.