An Arizona judge Wednesday rejected a death row inmate’s request for clemency based on claims he is mentally incompetent, keeping the execution on track to be the first in the state for nearly eight years. In 2008, Clarence Dixon was convicted of murdering 21-year-old Arizona State University student Deana Bowdoin in 1977 and sentenced to death.

Pinal County Superior Court Judge Robert Olson released his ruling after hearing oral arguments to determine whether Dixon’s execution should be stayed. Defense lawyers for Dixon argued that his psychological problems and schizophrenia make him mentally incompetent.

Olsen concluded that, while Dixon does suffer from schizophrenia, he “can rationally understand the State’s rationale for his death sentence and scheduled execution.” Lawyers for Dixon said they will appeal the ruling to the Arizona Supreme Court.

Arizona has not used the death penalty since July 2014 and currently has 113 prisoners on death row.

Human rights organizations like the ACLU criticize Arizona’s application of the death penalty. Although black people make up just 5.2 percent of Arizona’s population, they account for 16 percent of its death-row inmates. Additionally, Arizona is home to almost a quarter of Native Americans on death row.