Filmed at the state capitol building in Baton Rouge, LA, due to the feeling by Austin, TX, officials that filming in the actual location would not be in the best interests of citizens affected by the shooting.
In notes left prior to the incident Whitman requested an autopsy, to see if there was a medical reason for his uncontrolled aggression. Autopsies and post-mortems were performed, and they confirmed he had a congenital brain tumor, that had recently gone from dormant to active, and the tumor could have caused his aggression.
Police departments didn't have SWAT teams at the time of Whitman's shooting spree. The shooting spree has been credited as helping trigger the development of SWAT teams.
According to the book "Suicide by cop", Houston felt that Whitman could have shot him and Martinez, but he didn't because he was waiting for them to shoot him.
Houston McCoy and Ray Martinez, the police officers who shot Whitman, both sued MGM. Martinez sued because he felt he and his family were portrayed in a manner that perpetuated Hispanic stereotypes. His wife wasn't pregnant, and her ethnic background was German-American, not Hispanic-American. A disclaimer at the beginning of the movie reads: "Both the character and personality of Ramiro Martinez' wife and certain scenes about the Martinez family have been fictionalized for dramatic effect."