Four people were killed and a fifth was injured in a mass shooting at a Midtown Manhattan office building on Monday.

As more information comes out about the man who shot and killed four people inside a midtown Manhattan office building before turning the gun on himself, there is a question of whether he should have been allowed to keep his concealed carry permit.

Officials said the gunman fatally shot himself after his attack, which set off a chaotic scene that rippled out into the heart of Manhattan during rush hour.