Four people were killed and a fifth was injured in a mass shooting at a Midtown Manhattan office building on Monday. The injured victim was an employee at the NFL, according to NFL Commissioner Roger Goodell. Here's what we know about the four people killed:

An NYPD officer, a Blackstone executive, a Rudin Management associate and a security guard were killed in the shooting at Manhattan's 345 Park Avenue.

The victims of the Manhattan office building shooting are identified as NYPD Officer Didarul Islam, Blackstone executive Wesley LePatner, Cornell grad Julia Hyman and security officer Aland Etienne.