A Delaware man is suspected of robbing a series of stores in Pennsylvania and threatening to stab employees with hypodermic needles he claims contain HIV, according to KYW Newsradio.

Pennsylvania State Police have identified the suspect as 36-year-old David Cox of Wilmington, Delaware.

“His modus operandi for these robberies is that he enters the business and he approaches the employees while simultaneously exposing one or several hypodermic needles,” said Pennsylvania State Police captain David Young. “He appears to only be targeting those businesses that have young females working behind the counter.”

While it is not yet known whether Cox's needles actually contained fluids with the virus, police are assuming that they did and are treating them as weapons.