Attorneys for a former Missouri city official sentenced to death in Kansas for killing his estranged wife, their two daughters and his wife’s grandmother has asked Kansas’ highest court to throw out his conviction.

As a Kansas public defender specializing in death-penalty cases, Meryl Carver-Allmond told the Kansas Supreme Court on Friday there’s no dispute that her client, James Kraig Kahler, carried out the 2009 killings. But she argued that an accumulation of mistakes by the judge and prosecution during Kahler’s trial made those proceedings unfair to her client.

An attorney for the state pressed for Kahler’s conviction and sentence to stand, saying everything the trial judge did was legal.

Authorities say Kahler gunned down the four victims in his estranged wife’s grandmother’s home in Burlingame after losing his job as the water director in Columbia, Missouri, amid a contentious divorce.

Friday’s hearing was the first death penalty case heard by the state Supreme Court since Election Day, when voters opted to retain four justices who were targeted for ouster partly because the court overturned other death sentences