He worked as a wedding photographer for many years and had a wife named Patricia and a son named Tyler. According to Tyler, Phillip beat him and his mother regularly whenever he was home. When he worked he would find a young woman guest, out of town, buy and charm her into coming back to his hotel room so he could kill her. He would take pictures of what he did and keep them as trophies. One day Dexter Morgan notices this pattern of disappearances and tracks Barnes down. On May 19th, 2007 he follows him to an out of town job and picks him up after a wedding reception (where his picture is taken). He then takes a bloodslide and kills him.
His death was later investigated by Captain Maria LaGuerta and Lieutenant Debra Morgan in connection to the reopening of the Bay Harbor Butcher Investigation. Captain Laguerta tries to find evidence of the Butcher's identity but is stopped by Lieutenant Morgan as she hides the evidence and gives it to Dexter, who destroys it.