It has been determined that a Boise area inmate died of a lethal combination of methamphetamine and a psychoactive substance found in a specific plant species. Guards discovered the deceased prisoner in his jail cell several weeks ago.

A 42-year-old inmate in Garden City, Idaho, passed away in his sleep on July 25 at Ada County Jail due to a combination of methamphetamine and a substance known as Kratom, which is derived from the plant Mitragyna speciosa. Once extracted from the plant leaves, it is more commonly mixed with a liquid and consumed, resulting in hallucinations, liver damage and often death.

Prison officials believe Davis McClure slipped into a coma while asleep, and passed away. The coroner's report also stated that it was likely years of alcohol abuse leading to heart disease played a role. McClure showed no signs of being under the influence of any drugs when he was placed into his custody unit by jail staffers, according to information shared by idahonews.com.

The combination of methamphetamine and Kratom together can cause the failure of a person's liver and great neurological damage. Kratom is currently legal to produce and sell, in most states, as it is used commonly as a treatment for pain, as well as to alleviate stomach and digestive issues.

McClure is the third inmate in the Boise area to die in the past three weeks. Two prisoners at the Idaho Maximum Security Institution in south Boise, both committed suicide in late September.