The man used the syringe at a Baskin-Robbins to get an undisclosed amount of cash before escaping on foot.
"Some guy just walked in and said, ‘This is a robbery. This is a needle full of AIDS’, and then ‘Open the cash drawer’, and so I did,” cashier Katharine Pepin told KATU.
The 19-year-old saw what was in the suspect’s hypodermic needle. "It looked like a bloody substance,” Pepin said.
Pepin called 911 after the man ran off and returned to work her next shift the next night.
"At the moment I was terrified, and I mean I’ve been a little jumpy,” said Pepin. "I just don't want to work alone again. It definitely could have been worse. I feel pretty lucky.”