The reward for information about the whereabouts of missing Iowa college student Mollie Tibbetts, 20, has been increased to $172,000, according to Fox News. Previously, the reward—offered through a fund at a Brooklyn, Iowa, bank—was $30,000, the Des Moines Register reports. Rob Tibbetts, Mollie's father, tells Fox he hopes the increased reward will provide "financial incentive" for someone with information to step forward. He says he believes she is alive: "I'm thinking someone made a horrible mistake and they don't know what to do." In their search for the missing student, authorities have questioned a pig farmer with a history of stalking, as well a man accused of assaulting another jogger, and a man seen taking pictures of joggers. So far, these efforts have not yielded any leads. (More missing person stories.)