A fentanyl overdose killed two inmates of the Moberly Correctional Center who died within four hours of each other in early October, autopsy reports obtained by the Monitor-Index show.

Boone County Medical Examiner Carl Stacy, who conducted autopsies on Roland Tyler, 50, and Clayton King, 33, concluded that fentanyl killed Tyler and a combination of fentanyl and methamphetamine was responsible for King's death.

The autopsy reports were released under a Sunshine Law request to the Department of Corrections. As of press time, department spokeswoman Karen Pojmann had not responded to an email seeking comment about the deaths.

The deaths of Tyler and King were among four deaths at the prison in a 24-hour span in early October.

Tyler died around 9:50 p.m. Oct. 4, about four hours before King’s death.

Tyler was 15 years into a 20-year sentence for first-degree domestic assault involving serious physical injury, kidnapping and armed criminal action in Jackson County. Medical examiners found that he also had a rib fracture which was likely caused by the use of a defibrillator by prison medical staff. He was found unresponsive in his cell, according to the report.

Investigators told the medical examiners that there had been “a lot of traffic going in and out of his cell the night before,'' the reports state. Tyler was given naloxone, an “opioid antagonist,” but remained unresponsive.

King was serving the 13th year of his 14-year sentence for first-degree assault and robbery in Jackson County. He was also found unresponsive in his cell. Prison staff gave King naloxone and ketamine in an attempt to resuscitate him, according to the report.

The night before Tyler’s death, on Oct. 3, a corrections officer, Dallas Twyman, 27, was arrested after supervisors reportedly found a meth pipe, with residue, in his utility belt during a routine search.

However, there is no confirmed link between the arrest and either of the drug-related deaths.

Two other inmates, Walter Helgoth, 81, and Alphonso Calmes, 56, died Oct. 4, but both were due to natural causes. Calmes was initially given naloxone, but toxicology reports indicate he died of a heart attack stemming from coronary artery disease.