An Ohio prisoner convicted of raping and murdering a toddler in Akron in 1993 was put to death on Wednesday morning, the state’s first execution in more than three years.

The execution of Ronald Phillips, who was 19 when he killed Sheila Marie Evans, his girlfriend’s 3-year-old daughter, came amid a legal dispute about the constitutionality of Ohio’s execution method. After previous delays, a federal appeals court allowed the execution to proceed, and the United States Supreme Court declined to intervene.

Mr. Phillips was pronounced dead at 10:43 a.m. at the state penitentiary near Lucasville, a prison spokeswoman said.

Mr. Phillips and two other death row inmates facing executions had challenged Ohio’s three-drug execution method, arguing that the inclusion of midazolam, which is intended to render prisoners unconscious and insensate to pain, was cruel and unusual punishment.