Martinez said 56-year-old John Hoch, of Dyer, was taken into custody on Friday. He faces level 5 felony trafficking and level 6 felony official misconduct charges.
Hoch has been employed at the jail for the last 3.5 years. Martinez said an "intense investigation" over the past several months led to the charges against him.
The Lake County Sheriff's Department is still investigating many people may have been involved in the trafficking.
Authorities did not immediately provide further information.