Thief robs woman at knifepoint in UWS building lobby: cops

A thief robbed a 22-year-old woman at knifepoint in an Upper West Side building lobby, authorities said. 

The victim was heading uptown on the subway from the Financial District to buy a used turntable the evening of Jan. 10 when a man started following her, a police source said. 

Around 7:15 p.m., she entered the vestibule of an apartment building on West 101st Street near West End Avenue – where she was supposed to buy the record player – but her stalker went inside too and grabbed her cell phone, according to cops and the source.

When the woman resisted, the suspect put a knife to her throat, police said. 

He took off with her phone and ran to the 103rd Street No. 1 train station. The victim did not report any injuries.

The turntable seller, who felt sorry for the victim, ended up giving it to her for free, the sources said. 

In surveillance video released by the NYPD, the alleged robber is shown strolling on the sidewalk at West 40th Street and Eighth Avenue in the Garment District after the incident.

In a separate robbery report released by the NYPD late Monday, a group of suspects targeted a 13-year-old boy in Brooklyn’s Homecrest neighborhood.

The teen was standing around 3:10 p.m. Saturday on Coney Island Avenue near Avenue S when the group approached him and threatened to punch him in the face, cops said. 

Then they grabbed his cellphone, along with just $8, police said. 

The teen also did not report any injuries. 

Surveillance footage shows at least three suspects going in and out of a bodega on the snow-coated street. 

No arrests have been made in either case.