The family of Jacob Wetterling expressed condolences Wednesday a day in advance of the release of thousands of pages of previously unseen investigative documents from the 1989 abduction and murder of their 11-year-old son.

"Our hearts hurt for anyone who is pained or hurt from the release of this file," the statement from Jacob's parents Patty and Jerry Wetterling said.

Later, in a telephone interview, Patty Wetterling said that she is "fearful that there will be people hurt" by some of what is contained in the documents.

During the decadeslong investigation, victims had come forward wanting the people who had caused them harm to be investigated. A neighbor recently stopped by the Wetterlings' house, she said, to tell her that he had turned in his uncle and grandfather.

"All I could say is sorry, I'm so sorry," she said.

The Wetterlings fought unsuccessfully for the past year to keep some of the investigative files from public view, saying they contained extremely private material and cast blame on people who were ultimately not involved in Jacob's case. But a judge agreed earlier this year with Stearns County Attorney Janelle Kendall's reading of state law that said the entire file was public.

December 1989 Jacob Wetterling - abducted.

"It is difficult for us to relive those dark days," the family's statement said. "With time our family is healing and getting stronger and we appreciate all of the efforts to make things better for future victims of crime, their families and for all of us."

The abduction of Jacob at gunpoint on a rural road in St. Joseph, Minn., in October 1989 as he, his brother and best friend headed home from a convenience store shook the state and much of the region like few cases before or since. In the years that followed, Jacob Wetterling became a household name for generations of Minnesotans.

Until 2016, the boy's fate was a mystery. Late that summer, however, Danny Heinrich, who had been interviewed by investigators within a few months of Jacob's disappearance, confessed and pleaded guilty, saying he had killed Jacob shortly after he kidnapped him.

With Heinrich's plea and sentencing, the case file was closed. Under Minnesota law, once that happens, the file becomes public. Before it does, however, the victims — Jacob's family in this case — are allowed to review the file. The Wetterlings objected to the release of nearly 200 documents, but lost a yearlong court battle.

"When I first read the file, I didn't know if we would survive — or that I would survive, because Jerry's strong," she said in the phone interview, adding that the couple has since had time to "process and heal."

Patty Wetterling said she hopes that the huge number of documents are redacted so that victims' names remain private. "There's going to be people outed who didn't necessarily want it to be public," she said.

It's unclear how many pages will be released Thursday. Initial estimates said more than 56,000 pages were contained in the file. But in the past year, the federal government successfully sought the return of documents originated by the FBI. Those files are subject to federal privacy law and can be obtained only through Freedom of Information Act requests, if then.

Because the FBI documents were included in the file when Jacob's family reviewed it, Patty Wetterling said she was unsure what documents will become public Thursday.

"This is what I don't know," she said. "I'm sitting here with my hope socks on and my cookies baked, hoping everything is perfect."

News organizations and open government groups argued for the release of the entire Wetterling file. One of the plaintiffs in the lawsuit was the Silha Center for the Study of Media Ethics and Law at the University of Minnesota.

Professor Jane Kirtley, who leads the center, said of the documents, "I can't deny there may be people who will be embarrassed or hurt" by the content, but of greater importance is the public interest in oversight of law enforcement.

"This was hardly some obscure case, it captivated the public attention," she said.

Doug Kelley, the attorney for the Wetterlings, argued that state law, like federal law, should provide victims authority to shield investigative documents from the public.

Kirtley said a public review of the case documents ultimately serves victims because it ensures vigorous investigations with oversight of "a branch of government that is notoriously not open."

The Wetterlings have always avoided criticizing the investigation, saying that one man alone killed their son.

Their latest written statement encouraged people to hug their children, tell them they are special, say a prayer and light a candle.

The documents will be released on thumb drives after Stearns County Sheriff Don Gudmundson conducts a news conference at 10:06 a.m. Thursday.

Patty Wetterling said she will not be there. She will be en route to Washington, D.C., to the National Center for Missing and Exploited Children.

rochelle.olson@startribune.com jenna.ross@startribune.com