WAYNESBORO, Pa. - A 13-year-old boy told investigators he shot to death his younger brother when he became frustrated during a game of cops and robbers, police said in court documents made public Thursday.The Chambersburg Public Opinion reported that the 13-year-old, who has been charged with criminal homicide, used his father's gun to shoot his 9-year-old brother in the head Wednesday morning.The police affidavit used to support charges said the boys were in the living room when the 13-year-old got a loaded gun from the couch, one of two 9 mm handguns his father keeps there for security, the paper reported.MORE: CRIME AND PUBLIC SAFETY The 13-year-old boy told police he became angry that his brother was not listening to him, so he shot.