OLYMPIA — Gov. Jay Inslee promised Thursday to hold accountable the state employees who failed to fix a software problem allowing inmates out of prison too soon after the glitch was discovered in 2012.

Inslee said he has some “preliminary observations” of people involved but won’t act until an investigation is finished later this year.

“There is one thing that is going to happen at the conclusion of this investigation and that is state employees will be held accountable for this failure,” he said Thursday at the annual Associated Press Legislative Preview event.

“Because of the severity of this failure we are going to find out every document and every person associated with this failure,” he said. “There will be accountability for this failure.”

On Dec. 22, Inslee announced that as many as 3,200 prisoners have been mistakenly freed since 2002 because of the error in the algorithm used to calculate their sentences.

Since then prisoner sentences have been calculated by hand and more than two dozen offenders who need to serve additional time are back in custody, including four from Snohomish County.

Corrections officials also have tied the deaths of two people to convicted criminals who should have been locked up but were set free early in error.

Inslee said he spoke with the mothers of both victims.

“It was extremely painful,” he said. “They both were extremely gracious.”

The Department of Corrections first learned of the problem in 2012 and a fix was ordered. But the work was delayed 16 times and ultimately never done. Inslee ordered it be completed and it should be corrected by next week.

When the problem was first discovered, the Attorney General’s Office advised department officials it wasn’t necessary to manually recalculate prisoners’ sentences, according to documents released by the department.

The assistant attorney general assigned to the agency wrote in December 2012 that from a “risk management perspective,” a recalculation by hand of hundreds of sentences was “not so urgent” because a software reprogramming fix eventually would take care of the issue.

Inslee, who took office in January 2013, described the handling of the situation as a “serious misjudgment” on the part of some of those involved.

“The moment I heard about this, I understood what a failure this was,” Inslee said. “It was pretty obvious to me. Why it was not obvious to DOC officials, why it was not obvious to assistant attorneys general, is mindboggling.”

Attorney General Bob Ferguson, who also took office in 2013, voiced his dismay in a statement issued last month.

“This 2012 advice was deeply flawed and failed to emphasize the urgency of addressing this critical issue,” he said.

Ferguson directed his staff to review the internal processes that produced the advice and to find any other relevant legal advice on this matter, dating back to 2002.

Meanwhile, state lawmakers want to hear for themselves what happened.

On Monday, the first day of the legislative session, the Senate Law and Justice Committee will hold a hearing at which Secretary of Corrections Dan Pacholke is scheduled to appear.

A hearing in the House is expected later in the session.

Senate Majority Leader Mark Schoesler, R-Ritzville, on Thursday, expressed concern the investigation ordered by Inslee may not produce the most complete picture because the investigators were hired by the governor.

To call the probe objective, he said, “doesn’t smell right. We need to dive deep into it. We need to ask a lot of questions to get real answers … and not spin.”

Inslee tapped retired federal prosecutors Robert Westinghouse and Carl Blackstone to lead the investigation. He praised their integrity and said the problem shouldn’t be turned into a partisan issue.

“This is important to get to the bottom of this. We are going to do that,” Inslee said.

Lawmakers on Thursday said there may be legislation to prevent any recurrence.

House Speaker Frank Chopp, D-Seattle, suggested corrections officials carry out manual hand counts of prisoner sentences every year as a back stop to the computer calculations.

“We need to make sure this doesn’t happen again,” he said.

Jerry Cornfield: 360-352-8623; jcornfield@heraldnet.com