It happened on Tuesday, September 21 at 2:20 p.m. near Adam Clayton Powell Jr. Boulevard and West 129th Street.
The attacker followed the 76-year-old man into the vestibule of the building and then put him into a chokehold.
The robber took $500 in cash from the victim and then took off.
The elderly man suffered neck and ankle pain, but was not seriously hurt.
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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