OLYMPIA — A nearly two-month investigation into the early release of prisoners over a 13-year period found a series of missteps within the Department of Corrections and the lack of prioritization or follow up by several employees were to blame for the agency’s failure to quickly fix the error once it was brought to their attention.

Two former federal prosecutors, hired in late December by Democratic Gov. Jay Inslee, said in their report released Thursday that they found nothing in their investigation that was criminally actionable as a result of the programming error that led to the early release of up to 3,200 prisoners since 2002 because of miscalculated sentences. At least two deaths have been tied to the early releases.

The report said that the early releases were “caused by a series of errors coupled with bureaucratic incompetence, systemic failures of process and management, and an inexplicable failure both on an institutional and individual level to appreciate the fact that releasing even one inmate early, let alone thousands, undermined the core mission of the Department of Corrections, which is to protect the public,” the 52-page report reads.

At a news conference to announce the report, Inslee said he was “initiating various actions” against employees involved and would announce more on the results of that effort in the coming days.

“When mistakes of this kind happen with these kinds of consequences people need to be accountable and they will be held accountable,” he said. “This is not only about people. This is about a system that set them up for error.”

The report makes several recommendations, including requiring the state attorney general to review and approve all advice from that office to the Department of Corrections. It also calls for the agency to appoint an outside monitor, changes to the prioritization process for IT issues, and requiring assistant secretaries to be notified of any system wide errors affecting sentencing, release or supervision of offenders.

The report notes that the problem began with the agency’s move to comply with a July 2002 state Supreme Court ruling that required the Corrections Department to apply good-behavior credits earned in county jail to state prison sentences. However, an incorrect formula was entered in that ended up giving prisoners with sentencing enhancements too much so-called good time credit. The error went undetected for more than 10 years, and the agency was first alerted to the error in December 2012, when a victim’s family learned of a prisoner’s imminent release. The family did its own calculations and found he was being credited with too much time.

Assistant attorney general Ronda Larson advised the agency at the time that it wasn’t necessary to manually recalculate other prisoners’ sentences, saying that waiting for a programming fix for the other cases should be sufficient. However, that fix was repeatedly delayed for the next three years.

“Her advice appears to have played a part in DOC’s lethargic response to this problem,” the investigators wrote.

The report lists seven employees at the Department of Corrections who learned of the error, including previous chief information officers, records managers, IT analysts responsible for shepherding the fix and an assistant secretary who did not notify other high ranking officials in the agency of the error.

Of the seven, the report notes that Wendy Stigall, the records manager who learned of the problem in December 2012, “did an admirable job of notifying DOC managers and others of the problem and in initiating the computer fix.”

“Ms. Stigall waited for almost three years, however, to intervene or seek management involvement in light of the repeated delays by IT in correcting the early release date programming error,” the report says.

The release of the report comes as a Senate panel continues to hold public hearings as part of its own separate probe related to the error, which was publicly disclosed by the governor in December, shortly after he was notified about it.

Republican Sen. Mike Padden, the chairman of the committee, said it was important for the Senate investigation to continue to determine whether higher-level officials at the agency should be held accountable.

So far, three people — including Corrections Secretary Dan Pacholke — have resigned in the fallout from the error. Pacholke is still on the job until a replacement is named.

A software fix to the coding error was implemented last month.