The latest robbery, captured on shocking surveillance video, allegedly unfolded on Nov. 23 just after 6 p.m.
The suspect can be seen following the victim inside, grabbing his bag and tossing the 71-year-old victim to the ground. After that he can be seen tussling with the victim, flipping him over and patting him down, the video shows.
The attacker, described as in his 40s, 5-foot-8 and 180 pounds, then fled the building with an unknown amount of cash, cops said.
The victim was taken to a nearby hospital where he was treated for a broken arm.
Police refused to disclose the address of the attack.
The suspect is also wanted for a similar mugging on Nov. 3 in which he followed a 77-year-old victim inside his Gramercy building, shoved him up against a wall and stole his cash, according to cops.
Police refused to disclose the address of that assault, which was caught on surveillance tape, as well.
The Daily News said that attack occurred in Stuyvesant Town on First Avenue and East 16th Street.
Anyone with information is asked to call Crime stoppers at 1-800-577-TIPS (8477), log onto the Crime stoppers website at WWW.NYPDCRIMESTOPPERS.COM or text 274637 (CRIMES) then enter TIP577.