An anonymous reader writes: Governor Jay Inslee announced Tuesday that software used by the Washington Department of Corrections has been making mistakes in calculating sentences since 2002, resulting in thousands of inmates leaving prison early. Corrections officials learned of a problem in 2012. A patch to fix the faulty software will be implemented next month. Here's how the bug happened: When people are convicted of a crime, they're given a base sentence. On top of that, there can be extra periods of time — for example, using a firearm might add five years on top of the base sentence. While in prison, inmates can earn time off their sentence for good behavior or participating in work/education programs — but it can only apply to their base sentence. The software involved applied the inmates' good behavior credits to each section of their sentence. The Corrections Department is now trying to track down released inmates to make some of them finish their terms.