The gunman who killed four people, including an NYPD officer, reportedly had a grievance against the NFL and blamed football for issues with 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.

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.