Man Arrested and Charged with Murder in Lee County Cold Case

Richard Rahn
Special Agent in Charge

May 5, 2020

KEOKUK, Iowa – In April of 2017, the Division of Criminal Investigation's (DCI) Major Crime Unit and the Keokuk Police Department reopened the investigation into the June 2004 death of Bonnie Callahan, 73, of Keokuk.

On June 15, 2004, family members reported Callahan missing.  Later in the day, Callahan’s body was found along the bank of the Mississippi River front in Keokuk.  The circumstances surrounding Callahan’s death were considered suspicious. The investigation identified Nathanial Leo Ridnour, 34, as a suspect in Callahan’s homicide.

The Keokuk Police Department and the DCI 's Major Crime Unit provided an updated case briefing to the Lee County Attorney’s Office and the Iowa Attorney General’s Office (Area Prosecutions).  On May 4, 2020, an arrest warrant was issued for Ridnour for the murder of Callahan. Murder in the First Degree is a violation of Section 707.2(1) of the Code of Iowa, a Class A Felony. If convicted, the charge carries a life sentence without the possibility of parole. On May 5, 2020, Ridnour was taken into custody by the Delaware County Sheriff’s Office on the arrest warrant.  

This was a joint investigation by the DCI's Major Crime Unit, the Keokuk Police Department, the DCI Crime Scene Team, the Delaware County Sheriff’s Office, the Lee County Sheriff’s Office, the Iowa State Medical Examiner’s Office, the Lee County Attorney’s Office and the Iowa Attorney General’s Office (Area Prosecutions).  

Ridnour’s arrest is the eighth arrest related to the DCI Major Crime Unit conducting cold case homicide investigations in a three-year period in the southeast Iowa area.  These investigative results are a combined effort between a DCI Major Crime Unit initiative and local law enforcement partnership focusing on cold case investigations. 
Note: A criminal charge is merely an accusation and a defendant is presumed innocent until proven guilty.


The Iowa Department of Public Safety (DPS) is the largest law enforcement agency in the state. It includes six divisions and several bureaus, all working together with local, state and federal government agencies and the private sector, to keep Iowa a safe place by following our core values: leadership, integrity, professionalism, courtesy, service and protection. Divisions within the Iowa DPS: Iowa Division of Criminal Investigation, Iowa Division of Narcotics Enforcement, Iowa State Patrol, Iowa State Fire Marshal Division, Iowa Division of Intelligence and Fusion Center, and Administrative Services Division. The Department of Public Safety is led by the Commissioner who is appointed by the Governor.