Jeremy Harrison, 50, of Plainfield, Illinois, has been charged with computer tampering and official misconduct, both Class 3 felonies, following an investigation into his alleged misuse of Joliet's Flock surveillance system.

The investigation began in October 2025 after Joliet's inspector general asked Illinois State Police to examine allegations involving Harrison, who was serving as a lieutenant with the Joliet Police Department at the time.

State police and a special prosecutor presented the case to a Will County grand jury, which returned the felony charges. Authorities have not publicly disclosed what Harrison allegedly did with the Flock system or how it was supposedly used for personal benefit.

Flock's automated license plate reader technology records license plate numbers and other vehicle information, allowing law enforcement agencies to search camera data to determine when and where a vehicle was detected. The technology has become increasingly common among police departments as a tool for investigating crimes and tracking vehicles connected to cases.

The allegations against Harrison come as Joliet officials investigate another suspected misuse of the same technology.

On Sept. 4, the Joliet Police Department announced that a sworn officer and a public safety dispatcher had been placed on paid administrative leave after the department discovered alleged misuse of Flock technology. The department referred that matter to the city's inspector general and Illinois State Police for investigation. Neither employee was identified.

Joliet police said the department recognizes that surveillance tools must be restricted to legitimate law enforcement purposes and emphasized the importance of maintaining public trust.

“Maintaining that trust requires these resources to be used lawfully, appropriately, and only for authorized purposes,” the department said.

The charges against Harrison resulted from the grand jury investigation, but authorities have not released additional details about the alleged conduct. As with any criminal case, the charges are allegations, and Harrison is presumed innocent unless proven guilty in court.