Lt. Robert Oberosler came to the Yuma County Sheriff's Office after serving 8 years with the United States Marine Corps. Preparing for a challenging career in law enforcement, Oberosler worked as a Reserve Deputy and achieved his Peace Officer Status during his last three years in the corps. Joining the Sheriff’s Office full time in 1994, Oberosler served his first 2 years as a Deputy Sheriff stationed in the Gadsden area then was assigned to the Criminal Investigation Bureau. In 1997 Oberosler tested for and promoted to the rank of Sergeant. As a Sergeant he was assigned to the Professional Standards Bureau and supervised Patrol Squads, the Community Oriented Policing (C.O.P.) Unit, and the Yuma County Narcotics Task Force.
In October of 2010, Oberosler was promoted to his current rank of Lieutenant and continues to be the Yuma County Narcotics Task Force Commander. Lt. Oberosler is a graduate of the Northwestern University/Center for Public Safety, Police Command Staff School where he also received the Franklin M. Kerml Leadership Award.
Lt. Oberosler attended and successfully completed the Federal Bureau of Investigation National Academy in June 2011 in Quantico, Virginia.