Leadership

Lieutenant Colonel Gun Lee serves as Chief Deputy, Investigations Bureau, for the Loudoun County Sheriff's Office (LCSO) and joined the LCSO in 2022.

He previously served as Chief Deputy of Administration and Corrections, following a nearly 30-year career with the Fairfax County Police Department (FCPD). During his tenure with FCPD, he commanded patrol, major crimes, and internal affairs, and spent his last four years as Lt. Colonel and Deputy Chief of Police for Administration. In that capacity, he was responsible for the Criminal Justice Academy and the Administrative Support, Information Technology, and Resource Management bureaus.

Lieutenant Colonel Lee is a graduate of the FBI National Executive Institute and the Senior Management Institution for Policing. He earned a bachelor’s degree in business management and a master’s degree in public administration from George Mason University.

Lieutenant Colonel Robert “Bob” Mosier serves as Chief Deputy, Administrative and Corrections Bureau, for the Loudoun County Sheriff's Office (LCSO) and joined the LCSO in 2023.

He has more than 40 years of experience in federal, state, and local law enforcement, and in the private sector, most recently as the Secretary of Public Safety and Homeland Security for Virginia Governor Glenn Youngkin, where he also served on the Virginia Substance Abuse Services Council and Criminal Justice Services Board. He was elected twice as Sheriff of Fauquier County, Virginia, and previously served as Commander of Special Operations, the Patrol Division, and the Criminal Investigations Division there. He also worked for the U.S. Dept. of State and U.S. Dept. of Defense in support of international policing, and as Vice President of Investigations for the International Justice Mission.

Lieutenant Colonel Mosier earned a bachelor’s degree in criminal justice from Aspen University, an associate degree in special police operations from NOVA Community College, and a professional development certification from the Virginia Sheriff’s Institute at the L. Douglas Wilder School of Government and Public Affairs.

Lieutenant Colonel Christopher “Chris” Sawyer serves as the Chief Deputy, Field Operations Bureau, for the Loudoun County Sheriff's Office (LCSO) and joined the LCSO in 2005.

He previously served as Chief Deputy of Operations; Major in the Criminal Investigations Division; Major in the Administrative and Technical Services Division; Captain in the Criminal Investigations Division; and 1^st Lieutenant in the Field Operations Division, among other positions.

Lieutenant Colonel Sawyer is a graduate of the FBI National Academy, attended the Professional Executive Leadership School (PELS) and FBI-LEEDA Executive Leadership Institute, and earned a master’s degree in business administration, and a master’s degree in criminal justice and public administration from Liberty University.

Major Gregory “Greg” Ahlemann serves as Commander of the Operational Support Division for the Loudoun County Sheriff's Office (LCSO) and joined the LCSO in 1996.

He previously served in a wide range of positions, including Major of Field Operations; Captain and Station Commander for the LCSO’s Western Loudoun Station and Eastern Loudoun Station; as a 1^st Lieutenant in Field Operations; and as a deputy in patrol and motors. He left the LCSO in 2007 to work for the Shenandoah County (VA) Sheriff’s Office, then returned in 2012.

Major Ahlemann is a graduate of the FBI National Academy and attended the Professional Executive Leadership School (PELS), Supervisor Leadership Institute, Command Leadership Institute, and Executive Leadership Institute. He received the FBI-LEEDA Leadership Trilogy Award and attended Liberty University.

Major David Hill serves as Field Operations Division Commander for the Loudoun County Sheriff's Office (LCSO) and joined the LCSO in 2008.

He previously served as the LCSO’s Eastern Loudoun Station Commander; Administrative and Technical Services Assistant Division Commander; Ashburn Assistant Station Commander; Special Victims Unit Supervisor; and as a patrol supervisor.

Major Hill graduated from the 289^th session of the FBI National Academy. Major Hill also attended the 44^th session of the Professional Executive Leadership School (PELS) and the FBI-LEEDA Executive Leadership Institute. He earned a master’s degree in public administration from George Mason University, a master’s degree in forensic psychology from Argosy University, and a bachelor’s degree in diplomacy and foreign Affairs from Miami University.

Major Kimberly “Kim” Holway serves as Commander of the Corrections Division for the Loudoun County Sheriff's Office (LCSO) and joined the LCSO in 1995.

She previously served a wide range of positions, including Assistant Commander of Field Operations; Assistant Commander of the Ashburn Station; 2^nd Lieutenant and Sergeant in Patrol; Sergeant of the Narcotics Unit and Rapid Response Unit; and as a patrol deputy, Field Training Officer, and Community Resource and Corrections deputy. She was the LCSO’s first female firearms and rifle instructor, and the first female to serve on the LCSO’s SWAT team and as Assistant Team Commander.

Major Holway earned a bachelor’s degree in economics from Duke University and is an accomplished CrossFit athlete who competed in the Reebok CrossFit Games five times, winning the Masters gold medal in 2014.

Major Duy Nguyen serves as Commander of the Court Services Division for the Loudoun County Sheriff's Office (LCSO) and joined the LCSO in 2003.

He previously served as Captain in the Corrections Division; 1st Lieutenant and 2^nd Lieutenant in the Corrections and Court Services Division; Civil Unrest Unit Commander; and as Sergeant at the Adult Detention Center and Civil Enforcement Unit.  

Major Nguyen attended the Professional Executive Leadership School (PELS) and FBI-LEEDA Executive Learning Institute. He also attended both Strayer University and NOVA Community College.

Major Craig Schleiden serves as Commander of the Administrative and Technical Services Division for the Loudoun County Sheriff's Office (LCSO) and joined the LCSO in 1998.

He previously served as Captain and Assistant Commander of this Division as well as the Operational Support Division; Captain and Commander of the Emergency Communications Center; and in several capacities in the Field Operations Division as a 2^nd Lieutenant, Sergeant, field deputy, training officer, and dispatcher.

Major Schleiden attended the Professional Executive Leadership School (PELS) and the FBI-LEEDA Command Leadership Institute. He is a graduate of the NIJ Tech Institute and holds a Virginia DCJS LE Executive Certification from Georgetown University, among other certifications.

Major Robert “Rob” Tricarico serves as Commander of the Investigations Division for the Loudoun County Sheriff's Office (LCSO) and joined the LCSO in 2003.

He previously held positions as a Captain in the Criminal Investigations Division, as a 1st Lieutenant in the Field Operations Division, and as a 1st Lieutenant in the Operational Support Division. 

Major Tricarico earned a bachelor’s degree in wildlife sciences from Virginia Tech.