SEATTLE — A judge Wednesday ordered the Washington Attorney General’s Office to give him internal emails that might help explain when state lawyers handling a case about liability for the devastating Oso landslide realized that their expert witnesses were improperly deleting emails.

King County Superior Court Judge Roger Rogoff ordered the office to produce the emails within a week, saying it’s critical for him to know what they show as he considers punishing the state for allowing the destruction of potential evidence in the case.

“I’m just trying to figure out when y’all knew,” Rogoff told the state’s lawyers.

Attorney General Bob Ferguson has already acknowledged that one of his lawyers, Mark Jobson, knew for the past year and a half that experts hired by the state to determine the cause of the 2014 slide were deleting emails among themselves. But the office insists that its other lawyers were unaware, and that Jobson and the experts sincerely believed the emails did not need to be turned over to the plaintiffs and thus could be deleted.

During a hearing Wednesday, neither state Solicitor General Noah Purcell, who investigated the office’s handling of the matter, nor Rene Tomisser, senior counsel in the Attorney General’s Office, could definitively answer the judge’s questions, and Rogoff insisted on seeing any emails sent among state lawyers or between state lawyers and the experts that might shed light on the issue. The judge said he would review the messages in private rather than immediately turn them over to lawyers for the other side.

Rogoff noted that he was a prosecutor for 22 years before becoming a judge: “You’re sitting in a room with your agents, essentially, and they mention the word ’emails,’ and they mention the word ‘deletion,’ and someone isn’t jumping up and saying, ‘What?!'”

Purcell said the state was willing to provide the internal emails.

The landslide wiped out a rural neighborhood 60 miles northeast of Seattle on March 22, 2014, killing 43 people — the deadliest landslide in U.S. history. In lawsuits, victims or their families alleged that the state, Snohomish County or a company that logged above where the hillside collapsed have liability for worsening the damage or failing to warn about the danger; some claims have been dismissed, but some remain, with trial scheduled to begin in about a month.

Attorneys for the families said they were shocked to hear, during depositions this summer, that the experts had routinely deleted emails to each other as they studied the landslide — and that one of the state’s lawyers knew about it.

In asking the judge to punish the state, the victims’ lawyers argued that the experts tailored their findings to suit the state’s case, and that deleting the emails helped them cover their tracks. They asked the judge to hold the state liable for landslide damages, make a finding that the state knew or should have known of the danger the landslide posed or bar the state’s experts from testifying.

“These are very smart people and they don’t like the idea of lawyers getting inside their communications and cross-examining them on it,” John W. Phillips, a lawyer for the plaintiffs, told the judge.

The state’s lawyers rejected that assertion, saying the state spent $3 million to advance scientific knowledge in hopes of preventing further such catastrophes. The state turned over extensive raw data as well as other documents noting the significant scientific uncertainty about the factors contributing to the landslide, they said.

Purcell told the judge the experts didn’t believe they were doing anything wrong, because they acknowledged the practice openly during their depositions. The state has hired a private company to see whether the deleted emails can be recovered; about 1,000 have been provided to the plaintiffs’ lawyers, but it’s not clear how many more can be recovered.