Surveillance video released Thursday showed a frightening armed robbery at a gas station convenience store in Pasadena during which a store clerk was held at gunpoint while the robber emptied the cash register.

The robbery occurred around 11 p.m. Wednesday at a Mobil Gas station convenience store near South Lake Avenue and San Pasqual Street.

The video showed the robber as he entered the store, pulled out a gun and covered his face with a ski mask.

“I asked him ‘how can I help you’ and he … pointed the gun,” the clerk told KTLA.

The masked man pistol-whipped the cashier and was then seen holding a gun to the victim’s head as he emptied the cash register.

The cashier, who asked to remain anonymous, told KTLA the robber wasn’t satisfied with what was in the register and robbed him too.

The robber stole money the clerk was saving to send to his mother.

After the robbery, the masked man walked out of the store and disappeared before police arrived.