(AP) — More than 3,000 prisoners in Washington have been mistakenly released early since 2002 because of an error by the state's Department of Corrections that resulted in wrongly calculated sentences for about 3 percent of the prison population. At a news conference announcing the error Tuesday, Gov. Jay Inslee said he has ordered immediate steps to correct the longstanding computer glitch. Authorities say a July 2002 state Supreme Court ruling required the Corrections Department to apply good-behavior credits earned in county jail to state prison sentences. The Department of Corrections was first alerted to the error in December 2012, when a victim's family learned of a prisoner's imminent release. Inslee told corrections officials to stop releasing prisoners affected by the glitch until a hand calculation is done to ensure the offender is being released on the correct date. The governor said two retired federal prosecutors will conduct an independent investigation to figure out why it has taken so long to correct the problem.