Police say the man has robbed the Rite Aid store at West Wyoming and Rising Sun Avenues four times since October, three times in the last two weeks alone.
On each occasion, police say, the man took things from store shelves and left without paying.
Each time, a store employee tried to stop him. But police say the man pulled a knife and threatened to stab the worker.
On two occasions, the man was seen fleeing on foot south on Rising Sun Avenue.
The Rite Aid Corporation has joined forces with the Citizens Crime Commission and is offering a $1500 reward for the arrest and conviction of this suspect.
The suspect is described as an Hispanic man, 30-40 years old, 5'5"-5'7" tall, with a light complexion, light mustache, shaved head and bushy eyebrows.
Anyone with information is asked to call 911, or the Citizens Crime Commission at 215-546-TIPS.
