Four people were killed and a fifth was injured in a mass shooting at a Midtown Manhattan office building on Monday. The injured victim was an employee at the NFL, according to NFL Commissioner Roger Goodell. Here's what we know about the four people killed:

New York police honor fallen officer Didarul Islam with funeral services after he was killed by a gunman in a Midtown office building on Monday evening.

A group of friends from Thousand Oaks were among the victims of a mass shooting in Reno this week. The men had attended another friend's bachelor party before the shooting.

Two of the victims gunned down in a mass shooting at a Nevada Casino were in town to celebrate a bachelor party — and were shot in the back by a gunman whose seemingly random attack has left

The motive in Monday's mass shooting at a casino in Reno might forever remain a mystery. Police say the suspected gunman, 26-year-old Dakota Hawver, died overnight, the Reno Gazette Journal reports. Hawver,