San Jacinto Police officers responded to a report of a robbery at the San Jacinto Gas and Mini Mart at 2469 S. San Jacinto Street at 11:50 a.m. Wednesday.
Officers found the employee tied up and locked inside the building. The employee was medically treated after being freed.
A customer had called police after hearing a call for help from an employee inside the mart, according to police.
The employee told police a suspect entered the business at 10 p.m. Tuesday demanding money. The suspect bound the employee, locked the store and left.
The suspect was described as a Caucasian man wearing a dark-colored beanie to disguise his face, according to police.
Police released a composite sketch Thursday.
Anyone with information related to the suspect or the incident should contact the San Jacinto Police Department at (951) 537-6402.
The city of San Jacinto contracts with the Riverside County Sheriff's Department for police services.
