He waits in line at the pharmacy counter. But when it's his turn he doesn't pull out a prescription, he pulls up his shirt to reveal a gun.
"That's the only thing he gets is the prescription medication, he does not ask for cash and he does not get cash," Monica Munoz said.
Detectives said the most recent robbery happened on Monday. According to a worker, the suspect demanded Oxycontin. It's a powerful painkiller that's also highly addictive.
"It has the some of the same effect people say as heroin," RxNet Task Force agent Ernie Limon said. Limon said Oxycontin is worth a lot of money on the streets. "People are paying $80 to $120 for a pill."
Investigators said it is possible that the suspect is selling the pills. He's described as a thin man in his 20's. He has a goatee and acne scars on his face. He also walks with a limp.
A $1,000 reward is being offered for information leading to his arrest and conviction.