They are hoping surveillance images of the perpetrator will lead to an arrest.
"He is going to commercial establishments, demanding money, or he's hitting people on the street," NYPD Chief of Detectives James Essig said. "And a few instances when they don't comply right away, he is using physical force. But we want to grab him off the street before it does escalate into something tragic."
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The first incident happened around 11 p.m. on October 9, when police say the man entered the lobby of a Chase Bank on East 42nd Street and grabbed a 27-year-old woman from behind, displayed a knife, and demanded money.
The individual forcibly removed $150 from the victim's wallet before fleeing the scene.
The victim suffered injuries to her arm and refused medical attention.
The next day, authorities believe the same man struck again just before 7 p.m. at the Liberty Smoke Shop on 10th Avenue.
He went behind the register and held the 48-year-old worker at knifepoint while demanding money from the register.
He proceeded to strike the victim in the face multiple times with a closed fist before removing $580 from the register and fleeing.
The victim suffered injuries to his face and refused medical attention.
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Police believe the same man is responsible for 13 additional incidents between October 24 and November 1, sometimes robbing as many as three people in the same day -- all at knifepoint.
He is believed to have stolen well over $3,000 in total.
The most recent incident happened just before 10 a.m. Monday inside Peoples Place Gourmet Deli on Second Avenue.
He approached the victim, 63-year-old Santiago Gomez, and threatened him with the knife before stealing roughly $600 from the register.
"I see the guy here, and he put the knife in my stomach," he said. "I was scared...'Give me the money, give me the money,' I thought he was playing. But when I see the knife...I opened the case."
The individual is described as a male in his 20s or early 30s, approximately 5-foot-8 and and 150 pounds.
Anyone with information in regard to this incident is asked to call the NYPD's Crime Stoppers Hotline at 1-800-577-TIPS (8477) or for Spanish, 1-888-57-PISTA (74782).
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