SCHERTZ, Texas -- Schertz police are looking for clues into the shooting death of a security guard at an Internet gaming business.

Stewart Edelman, 44, was killed during an apparent robbery at My Internet Services at 500 Schertz Parkway, police said.

Three men entered the business at 3:20 a.m. and demanded money, police said.

A customer was pistol-whipped, police said. One of the men then fired several shots, wounding Edelman, who died upon arrival at Brooke Army Medical Center.

The customer was treated and released from a hospital for a head injury, police said.

The trio left the scene in a dark black or blue four-door car, police said.

Friends described Edelman as someone with a big heart who opened his home to friends in need and gave money to homeless people.

Anyone with information is urged to call 210-619-1200, or email to tipster@schertz.com.