Chicago Police Superintendent Garry McCarthy points to a poster showing three offenders that committed murders while on parole for prior gun convictions during a news conference in Chicago on Feb. 11, 2013. During the news conference McCarthy Chicago Mayor Rahm Emanuel and Cook County State's Attorney Anita Alvarez said they'll push for state legislation that increases the minimum sentences for those who violate the state's gun laws. (Associated Press)

Photo by: M. Spencer Green

Chicago Police Superintendent Garry McCarthy points to a poster showing three offenders that committed murders while on parole for prior gun convictions during a news conference in Chicago on Feb. 11, 2013. During the news conference McCarthy Chicago Mayor Rahm Emanuel and Cook County State's Attorney Anita Alvarez said they'll push for state legislation that increases the minimum sentences for those who violate the state's gun laws. (Associated Press)