An inmate at the Iowa State Penitentiary has been charged with second-degree murder in connection with the death of fellow inmate Gregory Allen Showalter Sr., who died on December 28, 2024, following a violent altercation. Showalter, 64, was serving a life sentence for the first-degree murder of his wife, Helen Showalter.
The incident occurred on December 19, 2024, in the prison kitchen, where Showalter and Anthony Michael Koehlhoeffer were involved in a verbal dispute while cleaning up after their shifts. According to court documents, Koehlhoeffer pushed Showalter to the ground and proceeded to assault him, delivering 21 punches and seven kicks or stomps to Showalter’s head and face during a brutal 25-second attack. Investigators confirmed that Showalter did not attempt to retaliate during the incident.
Dr. Melissa Blessing from the Johnson County Medical Examiner’s Office conducted an autopsy and ruled Showalter’s death a homicide due to blunt force injuries to the head.
The Iowa Department of Corrections initially did not disclose the circumstances surrounding Showalter’s death. However, Todd Copley, president of the prison staff union, had previously indicated that the death was a result of an inmate assault. Following the review of surveillance footage, authorities filed charges against Koehlhoeffer.
Koehlhoeffer, who is currently serving time for a second-degree robbery conviction from 2010, is scheduled for an initial appearance in Lee County on April 10 at 11 a.m. The tragic events leading to Showalter’s death raise serious concerns about the safety and management of inmates within correctional facilities.
