Immigrant-hating neo-Nazi J.T. Ready was not under the influence of alcohol or drugs when he went on a murderous rampage in early May in Gilbert, Ariz., killing four people before taking his own life, a newly released autopsy report says.

Jason Todd “J.T.” Ready, 39, died from a single bullet he fired into his own “right temporal scalp,” Maricopa County Medical Examiner Etoi Davenport ruled in the formal autopsy report. “The cause of death is gunshot wound of the head, and the manner of death is suicide,” the report said.

A “copper-colored jacketed gray metallic mushroom-shaped bullet” was recovered from the left side of Ready’s brain during the autopsy, according to the report, obtained by Hatewatch through an Arizona public records request.

Various body tissue and blood samples were taken during the May 4 autopsy and submitted for toxicology tests, which take some time to complete before the final report was released last week. Those toxicology screens looked for a lengthy list of chemicals and drugs, including cocaine, methamphetamine, codeine and antidepressants, with the finding of “none detected,” the report says.

At the time of his death, the 39-year-old Ready was running for sheriff of Pinal County, Ariz., billing himself as the “common sense choice” to stand up to “the horrific reality of terrible violence associated with illegal immigration.” For reasons that remain unexplained, he murdered his girlfriend and then three others before killing himself.

Ready, a former Marine who was twice court-martialed for bad conduct, went on to become a leader of the National Socialist Movement, an explicitly neo-Nazi group, before forming the militia-like group U.S. Border Guard. Heavily armed, Ready and others in his group conducted patrols on the U.S. border in an attempt to apprehend undocumented immigrants. That activity made Ready the focus of an FBI domestic terrorism investigation, but no charges were ever brought against him.

Before committing suicide at a home in Gilbert, Ready shot and killed his girlfriend, Lisa Lynn Mederos, 47; her daughter, Amber Nieve Mederos, 23; the daughter’s boyfriend, Jim Franklin Hiott, and Amber’s 15-month-old baby girl, Lilly Lynn Mederos. Investigators later found chemicals and military-grade munitions that apparently belonged to Ready at the residence.

“Apparently, the decedent [Ready] has a history of domestic violence with his girlfriend, who he lived with,” the medical examiner’s report said.