Testimony of Chicago cop climaxes stormy session of Civil Liberties Committee. Washington D.C. July 1. Testimony of Sergt. Lawrence Lyons, Chicago police officer in charge of one of the details participating in the Memorial Day riot in which 10 marching steel strikers were killed, climaxed a stormy hearing before the Senate Civil Liberties Committee today. He assumed a beligerent attitude in his denial that the police were "murderers". His testimony was frequently punctuated by the hisses of the spectators at the hearing and when he clashed with Chairman Lafollette. 7/1/37