Killeen police have released the name of a security guard who was fatally injured at a Killeen sandwich shop early Sunday morning.

In a media release, police said 58-year-old William Petty was pronounced dead at 5:20 AM.

Police found Petty suffering from a gunshot wound inside a Subway restaurant at 1100 Old FM 440 at 3:42 AM Sunday. He was transported to Temple's Baylor Scott & White Hospital, where he later succumbed to his injuries.

Detectives say a man entered the sandwich shop wearing a ski mask and approached Petty. During their confrontation, the suspect shot Petty, then fled. No other injuries were reported.

The suspect was described as a stocky black man standing 5'6" tall and wearing a gray sweatshirt, black shorts with red and white trim, and white athletic shoes.

Detectives ask that anyone who has information about this crime to contact Crime Stoppers at  (254) 526-TIPS, bellcountycrimestoppers.com, or via the P3 Tips mobile app.

Those submitting a tip do not have to reveal their name, and all information is anonymous and confidential.

Information leading to an arrest could net a cash reward of up to $1,000.