(CNN) - An 11-year-old boy disappeared on a dark rural road in central Minnesota on the night of October 22, 1989.
Jacob Wetterling of St. Joseph, his brother and a friend were coming home from a convenience store on bikes and a scooter when a man wearing a stocking mask and holding a gun approached.
He asked the boys their ages, grabbed Jacob and told the others to run into the woods or else he'd shoot, Jacob's father has said, recounting what his son told police.
Since then, no trace of Jacob has been found and no arrests have been made in the case, which was featured on John Walsh's "The Hunt."
On Thursday, law enforcement authorities in Minnesota called a press conference to talk about a development in the case that has gripped the state for 26 years.
Though no arrests have been made in the case, child pornography suspect Danny James Heinrich, 52, has been questioned in the abduction, authorities said.
"Given the nature of these charges and as a result of similarities between the abduction of Jacob Wetterling, a number of unsolved sexual assaults in central Minnesota dating back to the 1980s and the alleged criminal actions of Danny Heinrich, we consider him to be a person of interest in the Wetterling abduction," said FBI Special Agent in Charge Richard T. Thornton.
"Mr. Heinrich has been interviewed by investigators about the 1989 disappearance of Jacob Wetterling," said Andrew M. Luger, the U.S. attorney for Minnesota. "Let me be very clear. The defendant has denied any involvement in the disappearance of Jacob Wetterling and is not charged at this time with any crime related to that disappearance."
CNN sent an email and left a voice message seeking comment from Heinrich's attorney, public defender Andrew Mohring.
Heinrich was questioned in 1989, Stearns County Sheriff John L. Sanner said Thursday at a press conference. "This is not somebody new to us," he said.
Heinrich came back into focus after federal, state and local law enforcement officers decided to re-examine evidence using DNA testing technology that was unavailable in 1989, Luger said.
They discovered that Heinrich's DNA was found on the clothing of a victim in a kidnapping and sexual assault case that occurred about nine months before Jacob was abducted, said an FBI agent's affidavit attached to the criminal complaint against Heinrich.
In that incident, a man pulled a 12-year-old boy into a car in Cold Spring, a town about 10 miles from St. Joseph, and forced him to perform oral sex, the affidavit said. The man let the boy go after threatening his life.
Heinrich hasn't been charged in that case because the statute of limitations has expired, Luger said.
Federal agents used the DNA evidence to obtain a July search warrant for Heinrich's house in an effort to find evidence in the two abductions, Thornton said.
Agents found a large amount of video and printed child pornography, most of it concerning young boys, the affidavit said. Heinrich was charged with four counts of possession of child pornography and one count of receipt of child pornography. Court documents say the crimes occurred between August 16, 2009, and July 28, 2015.
Agents found several bins of boys' clothing and recordings of news reports of Jacob's abduction, the affidavit said.
The document says agents found hours of VHS tape, some of it shot with hidden cameras, of children riding bicycles, delivering newspapers and playing in public playgrounds.
The affidavit mentions eight sexual assaults of boys that occurred between 1986 and 1988 in Paynesville, a town about 28 miles from St. Joseph.
Heinrich was not charged in those attacks.
The assaults occurred within a mile of where Heinrich lived, the document says, and the general physical description of the attacker matches Heinrich's description at the time.
In some of the cases, the attacker would knock the boys off their bicycles and grope their genitals, the complaint said. Sometimes he wore a mask, asked their age or grade in school or threatened to kill them, the complaint said.
Heinrich will appear soon in federal court for a detention hearing, Luger said.
Jacob's parents issued a statement thanking law enforcement for staying on the case.
"We are so grateful for the prayers, the support and the hope shared in our search for Jacob and the search for answers," said Patty and Jerry Wetterling. "Who took Jacob? Where is he? What happened? Today we ask for a little time. We will be available for comment next week but ask for some space at this point in time."