ANAMOSA, Iowa - Both internal and external investigations are underway at the Anamosa State prison after the murder of two staff members last month.
Six security experts from South Dakota and Minnesota are looking into the killings as well as security policies and procedures at the prison.
Iowa's Division of Criminal Investigation and the Department of Corrections are also investigating.
Two workers died after being attacked by two inmates armed with hammers during an escape attempt.
Incarceration expert Martin Horn, who previously was Pennsylvania secretary of corrections and head of New York City's jail system, said Iowa should review its policies that would allow inmates to move about a prison unsupervised with tools
Last year, Iowa OSHA fined the Department of Corrections nearly $20,000 for workplace safety violations at the Anamosa prison.
Iowa OSHA said the prison didn’t have reliable radios and failed to follow its own emergency response plan. The department is contesting the citations and hearings are scheduled in July.
Correctional officer Robert McFarland and nurse Lorena Schulte were killed March 23 when they were attacked by inmates Michael Dutcher and Thomas Woodard
Dutcher and Woodard face first degree murder charges in the attack.