A little over twelve years since James Brown’s death, a CNN investigation is raising questions about the details surrounding his death and some close to the late singer are questioning whether he was murdered.

At least 13 people, including the doctor who signed the death certificate, Dr. Marvin Crawford, who knew Brown are requesting a criminal investigation into his death. Dr. Marvin Crawford revealed that he asked Brown’s daughter, Yamma Brown, for an autopsy, but she declined and has never given an explanation. Dr. Crawford revealed to CNN that Brown, whose official cause of death was a heart attack and fluid in the lungs, seemed like he was about to be discharged before he died. He explained, “He changed too fast. He was a patient I would never have predicted would have coded. … But he died that night, and I did raise that question: What went wrong in that room?”