Police say the victim, identified as Alfred Soto, was stabbed in the stomach and chest inside his West 96th Street building at around 10:20 a.m.
They say the stabbing occurred on the sixth floor inside an apartment, but not the one the victim lives in.
He was pronounced dead at Mount Sinai Morningside.
So far no one is in custody.
Police are working on a motive. The investigation is ongoing.
This story will be updated as more information becomes available.
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