The suspect targeted an Arco AM/PM on Inland Center Drive at 10 p.m. Monday, police said.
Authorities said the man showed the clerk a semi-automatic handgun and demanded money.
The suspect eventually stole an entire cash register and the drawer to another register.
San Bernardino police posted information about the robbery on Twitter, saying the suspect may be driving a silver Jeep.
Know him? He robbed Arco on Inland Center Dr @ gunpoint on 1/25 @ 10 pm. May have a slvr jeep. Call 9093845665 pic.twitter.com/5zC4EoGj6q
— San Bernardino PD (@SanBernardinoPD) January 27, 2016