Investigators believe he is responsible for at least 4 pharmacy robberies in Bensalem, Lower Southampton, and Warminster over the last month.
In each crime, the suspect wears a dark sweatshirt and partial mask. Police say he uses a large knife to force employees to fill the green bag he's holding with prescription pills.
The suspect may also be driving a silver SUV.
If you have any information on the robberies, call authorities.