Sulphur Springs police are investigating the armed robbery of a 58 year old man on Ava Street. Police say the suspect knocked on the victim’s door and pulled a silver handgun from his waistband and demanded money. The suspect then fled with an estimated $500 and remains at large. The suspect is a 25 – 30 year old black male, about 5-11 and weighing about 150 pounds. He had short hair and a long mustache. There were no injuries in the incident.