An Iowa State University sociology professor says the state’s prisons are so overcrowded, the state will probably have to build a new prison next year. Sociology professor Matt De Lisi says a new prison would cost about 45 million dollars to build, and it’d take about 30 million dollars each year to run it. De Lisi says with over 84-hundred inmates behind bars, Iowa’s prison system is about 120-percent over capacity.De Lisi says on top of that, there’s been a reduction in staff to guard the inmates, so in Iowa and many other states the question is not if a riot will occur, but when, where and how much damage it’ll cause. De Lisi says one reason the system’s overcrowded is because of a 1996 law change that forces the most serious criminals to serve at least 85 percent of their sentence. He says that means more inmates are staying longer, and reaching middle age.De Lisi says those older guys are “clogging” the system and won’t be released anytime soon.De Lisi says crime is a “young person’s game” and as offenders pass the age of 30, they grow increasingly less likely to commit another crime. De Lisi says the state, therefore, should try not to keep 40, 50, 60 and 70 year olds behind bars if there’s little chance they’ll commit another crime. De Lisi says even if the legislature acted immediately to reform sentencing laws to allow more paroles, there’d still be a need for another prison.Governor Tom Vilsack says he’s disappointed the Legislature isn’t moving quickly on sentencing reform. Vilsack says the issue seems to be derailed in the Legislature, and he says policymakers are going to have to “come to grips” with not acting. De Lisi issued a report today as part of the Iowa Public Policy Project, showing state spending on prisons has grown nearly 150 percent since 1990.