LAURENS, S.C.—A South Carolina man who killed a 2-year-old child found with bruises and bite marks all over his body and signs of sexual abuse has been sentenced to life in prison after agreeing to plead guilty. William Looper told investigators he beat and abused the boy for two weeks and couldn’t explain why, Solicitor David Stumbo said. When paramedics arrived at the Laurens home in June 2018, a dog was beside Brantley Justin Smith’s lifeless body and would not let anyone come near, The Index-Journal of Greenwood reported. The boy’s 6-year-old and 8-year-old brothers told investigators they heard their brother’s screams all through the night when he was killed, Stumbo said. Looper, 30, pleaded guilty to murder, first-degree criminal sexual conduct with a minor and two counts of unlawful neglect of a child. Prosecutors agreed to accept a life sentence without parole and not purse a possible death sentence …