The attacks against the men all happened in a span of 40 minutes in Williamsburg -- starting at 5 a.m. on Ross Street.
A 71-year-old man said three people came up from behind and pushed him to the ground. They went through his pockets, punched him in the face and then ran away with nothing.
The victim, later identified as David Greenfield, was taken to Bellevue Hospital for treatment of his injuries.
A half hour later, a 67-year-old man was followed by three men on Clymer Street.
They punched William Weiser in the face and went through his pockets, but again made off with nothing.
Just 10 minutes later on Wythe Place, the trio attacked a 56-year-old man. For the third time, they didn't find anything in the victim's pockets.
He was also taken to Bellevue Hospital.
So far, no arrests have been made.
Mayor Bill de Blasio said the NYPD is investigating the attacks and additional personnel will be added to patrol the area.
The NYPD is investigating these vicious attacks and our Hate Crimes division is on the scene. We'll be adding additional personnel to patrol the area and keep things safe. If you have any information or were a victim of these attacks, please contact 800-577-TIPS right away. https://t.co/fxfPbzZeCt— Mayor Bill de Blasio (@NYCMayor) August 12, 2019
Police believe the suspects fled into NYCHA's Taylor Wythe houses near the scene of the last attack.
Despite initially investigating the attacks as a hate crime, the NYPD later determined the motive in the attacks was robbery.
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