John Maki works for a prison watchdog group in Chicago.
He says Illinois has one of the most crowded prison systems in the nation.
But Maki says cramming people into cells only makes crime worse.
He spoke at Illinois Wesleyan University today as part of a social justice teach-in.
He says too often low level offenders are put away for behavior that could be fixed through counseling.
"Prison is really only good for one thing, which is incapacitating someone who poses a violent threat to public safety," said Maki. "If a person doesn't pose that threat we have to find different ways to hold them accountable."
Maki says Illinois spends $1.3 billion each year to keep its prison system in check.
He says if it enrolled offenders in drug rehab programs or mental health counseling, the state would be better off.