26-year-old jerome brown, a repeat felon. >> he served less than one year of his eight-year how manytoday? >> 16 right now. >> so we're 470 this morning. >> the cook county jail is the largest single site jail in the country, and it's overcrowded. >> we have a population that hovers between 10,000 and 11,000 people a day. >> the sheriff has to determine whether inmates pose a risk or not. >> i have no delusions. some of them the best thing we do for society is make sure they never see another human in their life. the majority of people in that jail are fixable, though. so with what limited resources i have, we work on them. >> liz visits cook county jail to see former fenger student jason barrett. one thing she's learned from her own family experience, people can change while they're in jail. >> my mom around 18 joined the convent where she stayed for almost 20 years. she met my dad. she was in cook county jail and she was doing ministry and stuff there. then they built this 14-year relationship. she kind of followed him around. she would visit him and she eventually left the convent