A female Blackstone executive has been named as the second victim of a Midtown Manhattan shooting that saw four people murdered.

Wesley LePatner, a 43 year-old senior managing director at the investment giant, was gunned down by Shane Tamura, 27, at Blackstone's New York headquarters at 345 Park Avenue Monday evening.

LePatner was a married mother of two. Her husband Evan works at private equity firm Courizon, with the couple and their children sharing a $7 million apartment on New York's Upper East Side.

Three others including NYPD officer Didarul Islam were also killed when a gunman identified as 27-year-old Shane Tamura walked into 345 Park Avenue and opened fire in the lobby.

Tamura also shot dead an unnamed security guard who tried to take cover behind a security desk.