Advances in DNA technology – and the courage of another young boy kidnapped in 1989 – were two of the keys in the long search for Jacob Wetterling.

For nearly 27 years, authorities had been searching unsuccessfully for any trace of Jacob.

Their break finally came last October when Danny Heinrich was arrested on federal child pornography charges. At the time, authorities signaled they were hoping for more.

“We consider him to be a person of interest in the Wetterling abduction,” Richard Thornton, the FBI’s Special Agent in Charge of the Minneapolis office, announced at a news conference with U.S. Attorney Andy Luger, Minnesota BCA Superintendent Drew Evans and Stearns County Sheriff John Sanner.

Danny Heinrich (Credit: KARE 11)

Danny Heinrich had actually been on their radar from the start. The FBI brought him in for questioning in December, 1989. They even put him under surveillance.

“We were hoping he would go someplace or do something that would lead us to evidence or to Jacob and he didn't," retired FBI supervisor Al Garber told KARE 11 last November.

But a piece of evidence gathered back then would prove to be a key to breaking the case more than two decades later.

It was the clothing another boy, Jared Scheierl, was wearing when he was kidnapped and assaulted months before Jacob.

When Jared told his story to KARE 11 – publically for the first time in 2004 – he revealed how investigators believed the same man had kidnapped both boys.

“I believe that it’s the same individual,” Jared said during the 2004 interview. “If it was soley my case, I would have probably just moved on.” Speaking out, he hoped, might help generate new leads in Jacob’s disappearance.

Scientific advances helped, too. “The DNA technology that we possess today is light years ahead of where it was,” said Evans.

When authorities used sophisticated new DNA testing on some of Jared’s clothing last year, court documents say they discovered a match to Danny Heinrich.

That new DNA evidence helped investigators to get a search warrant for Heinrich’s Annandale home on July 28, 2015.

Although they didn’t find evidence of the kidnappings, they did find binders filled with child pornography.

It was enough to charge Heinrich and use the threat of years in federal prison as leverage to help convince him to tell what he knew about Jacob.

MORE: Officials confirm Wetterling's remains found

That finally paid off last week when sources say Heinrich led authorities to a farm just outside Paynesville where they located some of Jacob’s clothing and human remains.

Over the weekend, authorities confirmed it was Jacob.

Officials may provide additional details when Heinrich is brought to court as early as Tuesday.