Police have released a surveillance video of the suspect, who they say approaches women on the street, grabs their purse and then takes off.
There have been four robberies in the last two weeks, all in the Brighton Beach section.
The victims are between the ages of 61 and 77 years old.
Minor injuries were reported in the incidents.
Anyone with information is asked to call the NYPD's Crime Stoppers Hotline at 800-577-TIPS. The public can also submit their tips by logging onto the Crime Stoppers Website at http://WWW.NYPDCRIMESTOPPERS.COM or texting their tips to 274637(CRIMES) then enter TIP577.
All calls are strictly confidential.
