The Lake County Sheriff's Office says 32-year-old Larry Stone discovered the glitch earlier this month. The phone system charges inmate accounts for calls but refunds the money if the call doesn't go through. But the system was reimbursing inmates twice for incomplete calls.
Authorities say Stone repeatedly made calls and hung up until he had more than $1,250 - enough to bond out of jail. Stone had been arrested in April on property-crime charges.
Stone was only free for a few hours before he was re-arrested. Officials became suspicious by the inmates' increased phone use.
The software error has been fixed and accounts restored to their previous totals.