The shooter behind a deadly rampage inside an office building in Midtown Manhattan on Monday evening was apparently targeting NFL offices there, New York City Mayor Eric Adams said Tuesday morning.Law enforcement sources say investigators recovered a three-page rambling note from gunman Shane Tamura's wallet in which he referenced the brain disease CTE.

A fifth shooting victim -- an NFL employee, according to Commissioner Roger Goodell -- was injured and taken to the hospital in critical condition, officials said. That victim was listed in stable condition on Tuesday morning, according to a source familiar with the individual's status.

Multiple casualties as gunman opened fire in the lobby of the midtown Manhattan building on Park Avenue that is home to the Blackstone investment firm and other corporations before moving to other floors.