• Colonel Linda Mandat
• Deputy Director

Colonel Linda Mandat was appointed as Deputy Director of the Division of Internal Investigation in January 2025. She has over 24 years of experience with the Illinois State Police (ISP). Colonel Mandat has served the ISP in many roles, most recently as the Division of Forensic Services Assistant Deputy Director. Prior to that, Colonel Mandat served as the Major of Strategic Operations Command and District Commander of District 2 (Elgin) and District 15 (Downers Grove) in the Division of Patrol. Colonel Mandat was an Investigative Commander at the Division of Internal Investigation, and a Docksite Supervisor and Sergeant at Statewide Gaming Command. Colonel Mandat held assignments in the Division of Criminal Investigation where she worked narcotics and general criminal investigations. Colonel Mandat began her career in District 2, where she was assigned to patrol as well as the Special Enforcement Team.

Colonel Mandat completed the Northwestern University School of Police Staff and Command, Northwestern University Supervision of Police Personnel, Illinois Law Enforcement Training and Standards Board Executive Institute Police Executive Role in the 21st Century, FBI – LEEDA Executive Leadership Institute, and the University of Florida - Diversity, Equity, and Inclusion in the Workplace certificate. Colonel Mandat graduated with a bachelor’s degree in Business from Elmhurst University.

• Lieutenant Colonel Jose De Jesus
• Assistant Deputy Director

Lieutenant Colonel Jose De Jesus was appointed as Assistant Deputy Director of the Division of Internal Investigation in November 2023. Lieutenant Colonel De Jesus has 18 years of experience with the Illinois State Police and his past assignments include District Chicago Patrol, Medicaid Fraud Investigations, Deputy Chief Public Information Officer, Operations Officer District 21 Patrol, Commander District 5 Patrol, and Northern Commander for the Division of Internal Investigation.

Lieutenant Colonel De Jesus was born in Chicago, Illinois where he attended Lane Tech High School, and earned a Bachelor of Science Degree in Biochemistry from the University of Illinois at Chicago. Lieutenant Colonel De Jesus is also a veteran, having served in the U.S. Marine Corps Reserves.

• Commander Natasha Lawson
• Southern DII Commander

Captain Natasha Lawson serves as the Southern Commander of the Division of Internal Investigation (DII), which handles 75 counties in Southern Illinois. Captain Lawson has over 17 years of experience with the Illinois State Police.

In 2006, Captain Lawson joined the Illinois State Police (ISP) and, upon graduation was assigned to District 15 Patrol. Captain Lawson’s diverse background includes the following past assignments with the ISP: The Division of Operations, the Division of Administration, the Public Information Office, the Statewide Recruitment Coordinator under the Equal Employment Opportunity Office, the Chief of Staff for the Legal Office, and as a Bureau Chief at the Division of the Academy and Training.

In 2011, Captain Lawson was a case agent in DII and attended the Basic Investigator Course (BIC). In March 2021, Captain Lawson returned to DII as the Chief of Staff, transitioned into the Springfield Investigative Commander role, and was promoted to the Southern Commander in December 2023.

Captain Lawson was born in Chicago, Illinois, and attended Proviso West High School. She holds a Bachelor of Science in Aviation Administration with a minor in Criminal/Social Justice from Lewis University in Romeoville. She’s a member of Alpha Kappa Alpha Sorority, Inc., which provides community service nationwide. She is also a paralegal, attaining her American Bar Association certification in Paralegal Studies from Roosevelt University in Chicago.

• Commander Jose Chairez
• Northern DII Commander

Commander Jose Chairez serves as the Northern Commander of the Division of Internal Investigation, which handles 27 counties in Northern Illinois. Commander Chairez has 16 years of experience with the Illinois State Police.

Commander Chairez graduated from the Illinois State Police Academy in 2009 and was assigned to patrol in District 15 (Chicago area expressways), where he served until 2012. From 2012 to 2014, he worked in the District 15 Investigations Unit. In April 2014, he was assigned to the Division of Criminal Investigation Zone 1 and the DuPage Metropolitan Enforcement Group (DUMEG), where he served until 2023. While in DUMEG, Commander Chairez earned Special Agent status and was promoted to Sergeant, then Master Sergeant, prior to being named Deputy Director of DUMEG. In 2021, he was appointed Director of DUMEG, a position he held for two years. In December 2023, Chairez was promoted to Lieutenant of DCI Zone 1’s Firearms Investigation Unit, Public Integrity Task Force, and acted as the ISP Liaison to all Zone 1 Major Crimes Task Forces.

Commander Chairez was appointed to lead the Division of Internal Investigations Northern Command on January 1, 2025.

Commander Chairez was born in Zacatecas, Mexico, and raised in the northwest suburbs of Chicago. He is a graduate of the University of Evansville (2005) and served in the United States Marine Corps Reserves (2006 to 2014).