The Powell County coroner said Wednesday that a 23-year-old Billings man serving a life sentence at Montana State Prison for murder died last month of a drug overdose.
Coroner John Pohle said an autopsy by the Montana State Crime Lab found Cleveland Benjamin Boyer died from “mixed drug toxicity.”
Pohle referred further questions about the drugs found in Boyer’s system to Powell County Attorney Lewis Smith, who said he could not comment on that matter.
Smith said Boyer’s death is being reviewed by his office, and a decision has not yet been made on whether a coroner’s inquest will be held.
State law requires a corner’s inquest under most circumstances when a prison or jail inmate dies, or when law enforcement is involved in the death. The inquest is held to determine the cause of death and whether the death was the result of a criminal act.
Montana State Prison spokeswoman Linda Moodry said Wednesday that prison authorities had no new information about Boyer’s death.
Boyer died Aug. 23. Prison staff were summoned to his cell by another inmate shortly before 9 a.m.
Boyer was pronounced dead at a hospital in Deer Lodge.
Prison officials said at the time that there was no sign of foul play and no evidence that Boyer had committed suicide.
An autopsy was to be performed at the state crime lab in order to determine how Boyer died.
Boyer was sentenced in January to life in prison, plus 20 years, for the murder of Danny Valenzuela.
Valenzuela was shot numerous times outside a downtown Billings convenience store on March 13, 2011. He died six days later.
Boyer was convicted of deliberate homicide and felony tampering after a six-day trial in November 2012.
Boyer attempted suicide in the Yellowstone County jail in June 2011 by cutting his own throat.
Authorities said Boyer, whose injuries were not life threatening, was distraught over the death of his mother in a house fire.
On Tuesday, the Montana Supreme Court dismissed an appeal filed in April on Boyer’s behalf by a state public defender.