Kotha Govardhan Reddy, who had moved to the US seven years ago, was allegedly attacked by a group of men inside the store in Florida's Pensacola city. According to reports, the accused who shot him was African-American.
Another employee of the store was injured in the attack, news agency IANS reported.
Reddy, who is from Telangana's Yadadri district, is survived by his wife and two daughters, both in school.
"We got information that a masked man shot dead Govardhan when he was alone at the store and fled away. As per preliminary information, the accused did not take away any cash. The motive of the killing is not known," said Reddy, a friend of the victim, according to news agency PTI.
His family has asked the centre to help them in bringing back the body home, IANS reported.