Meet the Command Staff
Colonel Michael A. Williams
Colonel Michael Williams began his law enforcement career in 1990 at the Cobb County Sheriff’s Office. His career started as a deputy in the Adult Detention Center where he now serves as the Division Commander. During his career, Colonel Williams also worked in Field Operations Uniform Patrol, Transport, at the joint agency narcotics unit known as MCS, and he worked as a hostage negotiator on the SWAT Team. Before joining the Cobb County Sheriff’s Office, Colonel Williams served four years in the United States Army. He was born and raised in Marietta and graduated from Sprayberry High School.
Colonel David Gallmon
Colonel David Gallmon began his law enforcement career in 1991 as a Cobb County police officer, working his way up to the rank of captain. He was previously the Precincts 2 and 5 commander. Over the course of his career, Gallmon handled critical incidents to include SWAT, hostage negotiations, and suspected bomb threats. Gallmon served in the United States Air Force with assignments that included Ballistic Analysis Technician for the Titian II nuclear weapon system and Air Traffic Controller. After leaving active duty, he went on to serve in the United States Air Force Reserves until 2003. Gallmon received a Bachelor of Science degree in Aeronautics from Embry Riddle Aeronautical University and a Master’s Degree in Public Administration from Command College, Columbus State University.
Colonel Ryan Mehling
Colonel Ryan Mehling has been employed with the Sheriff’s Office since 2000. As a deputy, Mehling worked in the Detention Division, Domestic Violence Unit, Forgery Unit, Transport Unit, and Uniform Field Operations. While working Forgery, Mehling was promoted to the rank of sergeant in 2007 and subsequently promoted to the rank of lieutenant in 2013, and major in 2016. He has also served in the Criminal Investigations Unit and in Internal Affairs. In September of 2019, Mehling was appointed to the rank of Lieutenant Colonel and served as the assistant division commander of the Uniform Field Operations Division. In April of 2022, he was appointed to the rank of Colonel and oversees the Uniform Field Operation Division.
Commander Mehling graduated from Kennesaw State University in 2000 where he earned his Bachelor of Science in Psychology. He is married with one child and attends St. Ann’s Catholic Church in Marietta.
Colonel Eric Yeager
Colonel Eric Yeager is a career law enforcement professional, having joined the Cobb County Police Department in 1988. He served for 32 years, working in numerous departments across the agency including the Fatality Investigations Unit, the Criminal Investigations Unit Commander and the Special Victims/Crimes Against Children Unit Commander before retiring in 2020 as the Assistant Commander in Precinct 2. Colonel Yeager joined the Cobb County Sheriff’s Office in January 2021 and leads the Criminal Investigations Division which encompasses Crime Scene Investigations, Domestic Violence Unit, Evidence Unit, Forgery and Fraud Unit, Fugitive Unit, Marietta/Cobb/Smyrna Narcotics Unit, and Sex Offender Unit. He is a graduate of Fairmont State University. He has completed numerous supervisory programs including the Government Management Development Program from the University of Georgia’s Carl Vinson Institute. He is married with three children and resides in Cobb County.
Lieutenant Colonel David Hilsman
Lieutenant Colonel David Hilsman began his career with the Cobb County Sheriff’s Office in 2001. As a deputy, Hilsman worked in the Detention Division, Domestic Violence Unit, Courts, SWAT, and Uniform Field Operations. While working Uniform Field Operations, Hilsman was promoted to the rank of sergeant in 2011 and subsequently promoted to the rank of lieutenant in 2017, and major in 2019. He has also served in the Criminal Investigations Unit. In May of 2023, Hilsman was appointed to the rank of Lieutenant Colonel where he serves as the Assistant division commander of the Adult Detention Center.
Lieutenant Colonel Hilsman graduated from Kennesaw State University in 2000 where he earned his Bachelor of Science in Psychology. He graduated from American Military University earning his Master’s degree in Strategic Intelligence in 2011. He has completed numerous supervisory programs including LDIG Command-Level Preparation Program from Georgia State University and the FBI-LEEDA Trilogy series. He is married with three children.
Lieutenant Colonel Clifford Kelker
Lieutenant Colonel Clifford Kelker began his law enforcement career with the Marietta Police Department in Marietta, Georgia in 1991. He went on to become the chief of police in Jonesboro, GA in 2018. A military veteran, he served over seven years in the United States Army and deployed with the 101st Airborne Division to Operation Desert Shield and Operation Desert Storm. Kelker joined the Cobb County Sheriff’s Office in 2021, where he leads the Criminal Investigations Division. Kelker earned a Bachelor’s Degree in Public and Social Services and a Master’s Degree in Public Administration from Kennesaw State University. He has completed several executive management training courses to include being a graduate of the 55th Session of the Senior Management Institute for Police (SMIP) at Boston University and the 106th Session of the Administrative Officers Course at the Southern Police Institute on the campus of the University of Louisville. He also completed the Carl Vinson Institute of Governance-Management Development Program, the International Association of Chiefs of Police-Leadership in Police Organizations course and is a graduate of the Dale Carnegie Leadership course receiving the highest award.
Lieutenant Colonel Dewayne Morris
Lieutenant Colonel Dewayne Morris began his law enforcement career at the Powder Springs Police Department and then went on to join the Cobb County Police Department achieving the rank of sergeant.
He has previously worked as an explosives expert for the Georgia Bureau of Alcohol, Tobacco, and Firearms. Morris has also been a peace officer for the Cobb County Board of Education.
Lieutenant Colonel Dewayne Morris joined Sheriff Owens’ administration and oversees a number of administrative functions.
Lieutenant Colonel Arthur Peralta
Lieutenant Colonel Arthur Peralta began his law enforcement career in 1982 as a Law Enforcement Specialist in the United States Air Force. After serving ten years of active duty service, he joined the Santa Fe Police Department in Santa Fe, New Mexico. He served as a Patrol Officer, Juvenile Services Commander and, upon being promoted to Lieutenant, the Accreditation Manager. Lt. Colonel Peralta joined the Bureau of Alcohol, Tobacco, Firearms and Explosives and served twenty years stationed in California, Washington D.C., Texas, and Georgia. He most recently served as the Special Agent in Charge, overseeing all ATF operations in the State of Georgia. Lt. Colonel Peralta holds a Bachelor’s Degree in Human Services from Wayland Baptist University, Plainview, Texas and a Masters Degree in Security and Safety Leadership from George Washington University, Washington D.C.
Lieutenant Colonel Rebekah “Becky” Westenberger
Lieutenant Colonel Rebekah Westenberger began her career with Cobb County Sheriff’s in May 1997. During this time Lieutenant Colonel Westenberger was assigned to various areas, through the ranks, including the Adult Detention Courts, Courts, Inspectional Services, Operations, Public Outreach, Recruiting, and Training. In August 2019, Westenberger was appointed to lieutenant colonel assigned to the Adult Detention Center. She also leads the Sheriff’s Office Color Guard. Westenberger is a graduate of South Cobb High School. She received her BA in Criminal Justice Administration, graduating Cum Laude, from Columbia Southern University. She is involved with Special Olympics Georgia, the Metropolitan Atlanta Police Emerald Society as well as her church, First Baptist Church of Atlanta. Lieutenant Colonel Westenberger currently resides in Powder Springs.
Lieutenant Colonel Michael L. Williams
Lieutenant Colonel Michael L. Williams began his law enforcement career in 1986 at the Virginia Department of Corrections, where he served for 9 years. He started his career at the Cobb County Sheriff’s Office in 1996 as a deputy in the Adult Detention Center. During his career, Lieutenant Colonel Williams has also worked in Field Operations uniform patrol, where he is now the Assistant Division Commander. He served on the Sheriff’s SWAT Team for 25 years, reaching the position of SWAT Team Commander. He also has supervised the Sheriff’s Office Transport Unit, FAST Unit, Domestic Violence Unit, Sex Offender Unit and worked for four years as the South Cobb High School Resource Officer. Before starting his law enforcement career, Lieutenant Colonel Williams served in the United States Marine Corps.