Chief Hamner previously served as Police Chief with the City of Bainbridge Island, Washington, where he held the position since 2013. Prior to appointment as Police Chief with the City of Bainbridge Island, he held numerous positions with the City of Indianapolis Police Department over a period of 23 years. During his time with the Indianapolis Police Department, he advanced to the rank of Major and served as the Chief's Executive Officer. He has held positions as commander of a Narcotics Unit, Neighborhood Resource Unit, SWAT Intelligence Sergeant Team Leader, Operations Sergeant, South District Detective Unit Supervisor, and Patrol Officer.

Chief Hamner has a Master of Criminal Justice and Public Safety degree from Indiana University and is a graduate of the FBI National Academy Class 245. He has an FBI Command College Certificate, DEA Drug School graduate, Senior Management Institute for Police graduate, and is highly decorated with 19 commendations, including the Medal of Valor and Unit Citation. Chief Hamner joined the City of Banning in February 2019.