Instagram/Robert Allen & Michael Bo Music Key witness in XXXTENTACION's murder freed after serving a 5-year sentence for his cooperation in the 2018 trial. March 31, 2026 AceShowbiz - One of the individuals involved in the 2018 killing of XXXTENTACION has been freed after serving a five-year prison sentence. Robert Allen, charged alongside three others in the rapper's murder, completed his sentence following a plea agreement. He became a pivotal witness after agreeing to cooperate with prosecutors, pleading guilty to second-degree murder and armed robbery.