(CNN) -- Two Ohio correctional officers have been placed on leave as investigators look into the suicide of Cleveland kidnapper Ariel Castro, a spokeswoman for the Ohio Department of Rehabilitation and Correction told CNN.
Caleb Ackley and Ryan Murphy, both hired in 2007, were on duty in the prison unit where Castro was housed the night he hanged himself.
Castro, 52, was found hanged with a bedsheet September 3, coroner Dr. Jan Gorniak said. He was being held at the Correctional Reception Center in Orient.
Prison medical staff tried to revive him.
Castro pleaded guilty last month to 937 counts, including the kidnapping of Michelle Knight, Georgina DeJesus and Amanda Berry. He was sentenced to life plus 1,000 years.
CNN's Kevin Conlon contributed to this report.