Investigators missed opportunities early on to catch the man who kidnapped and killed 11-year-old Jacob Wetterling in 1989, a Minnesota sheriff said Thursday before releasing thousands of investigative documents in the case that focused national attention on missing children.

Stearns County Sheriff Don Gudmundson said at a news conference that the investigation "went off the rails" decades before the suspect was finally caught.

"Our wish was this case would have turned out differently and better," said Gudmundson, who was not sheriff at the time of Jacob's abduction. "Stress and anxiety put us into tunnel vision." He added: "All of us failed."

Danny Heinrich, 55, confessed to killing Jacob and led investigators to his remains in 2016. In a deal with prosecutors , he was sentenced to 20 years in prison for child pornography.

The sheriff revealed that a drunken Heinrich was arrested at a bar in Roscoe in central Minnesota, in February 1990, a few months after Jacob was kidnapped by a masked gunman near his home in St. Joseph, about 20 miles (30 kilometers) away, in October 1989. But Gudmundson said inexperienced FBI profilers concluded after an interrogation that Heinrich did not abduct Jacob.

Gudmundson said there were "about 20 things" investigators should have pieced together that pointed to Heinrich. The sheriff said a shoe print and tire tracks at the scene tied Heinrich to the abduction, and the odds were "not just slim but minuscule" that both those prints and tracks belonged to someone else.

In January 1989, a Cold Spring boy was kidnapped and sexually assaulted in a vehicle that he later said matched the interior of Heinrich's car. But Gudmundson said a law enforcement task force waited a month after Jacob's abduction that October before making a connection to the earlier attack.

The sheriff also cited similar assaults in nearby Paynesville leading up to Jacob's abduction that were carried out by a heavyset man who wore face paint or a mask, spoke in a deep, raspy voice and threatened victims with a gun. Instead, the task force focused on another man, even though Heinrich failed a polygraph test given by law enforcement, Gudmundson said.

Former FBI agent Al Garber, who supervised the original investigation in 1989, called Gudmundson's analysis unfair.

"He didn't see the day-to-day operations," Garber said. "He doesn't know."

Jacob's parents, Patty and Jerry Wetterling, fought to keep some documents private, saying they contained personal information. But media organizations convinced a judge that the documents were public information under state law because the investigation was over.

Gudmundson released about 42,000 pages of files from local and state investigators. Federal documents were not included.

Jerry Wetterling attended the news conference but declined to comment. On Wednesday, the Wetterling family issued a statement saying it is "difficult for us to relive those dark days. 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."

Patty Wetterling became a national advocate for missing children after Jacob's disappearance. A 1994 federal law named for Jacob requires states to establish sex offender registries.