Officer Safety Act of 2012 - Amends the federal judicial code to deem a law enforcement officer who is the defendant in a criminal prosecution to have been acting under the color of his office (solely for purposes of determining the propriety of removal of the case to U.S. district court) if the officer: (1) protected an individual in the officer's presence from a crime of violence; (2) provided immediate assistance to an individual who suffered, or who was threatened with, bodily harm; or (3) prevented the escape of any individual whom the officer reasonably believed to have committed, or was about to commit, in the officer's presence, a crime of violence that resulted in, or that was likely to result in, death or serious bodily injury.