Four people were killed and a fifth was injured in a mass shooting at a Midtown Manhattan office building on Monday.One slain victim worked at Rudin Management -- which is located on the 33rd floor of 345 Park Avenue,

The alleged gunman at a shooting rampage in a midtown Manhattan office building was identified as 27-year-old Shane Tamura, of Nevada.

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.