Authorities announced Saturday that they had located the body of Jacob Wetterling, who was abducted at gunpoint in 1989. (CBS Minnesota)

Nearly 27 years ago, a man wearing a mask and holding a gun approached three boys riding bikes in rural St. Joseph, Minn.

He told the boys to lie facedown in a ditch and asked them their ages — 10, 11 and 11.

The man latched on to Jacob Wetterling, then told the other boys to run away and not look back. They ran away, but when they did look back, Jacob and the man had vanished.

On Saturday, after nearly three decades of searching, authorities announced that they had identified the remains of Jacob on a farm in the same county where he disappeared.

The announcement ended a mystery that had rankled police and worried parents, but it destroyed the last shred of hope for Jacob’s family of finding him alive.

In the intervening years, the Wetterlings had become advocates, lobbying for laws that kept tabs on the nation’s sex offenders and marshaled resources to quickly locate missing children.

Authorities announced on Saturday that they had located the body of Jacob Wetterling, who was abducted at gunpoint in 1989. (The National Center for Missing and Exploited Children) Authorities announced Saturday that they had located the body of Jacob Wetterling, who was abducted at gunpoint in 1989. (National Center for Missing and Exploited Children)

In 1994, the federal Jacob Wetterling Crimes Against Children and Sexually Violent Offender Registration Act led to the creation of a national sex offender registry. The Minneapolis Star-Tribune called the Wetterlings and the foundation they established “the driving force” behind the registry.

Every Oct. 22, on the anniversary of Jacob’s disappearance, Minnesotans kept their porch lights on in his memory.

The search for Jacob spanned continents, according to a timeline compiled by the Associated Press. In October 1990, an FBI spokesman told the AP that investigators chased 50,000 leads in Jacob’s disappearance and interviewed 2,000 people.

Danny Heinrich, who had been one of the first people interviewed in Jacob’s disappearance, led investigators to the boy’s body last week.

It was unclear Sunday what sparked Heinrich’s cooperation. But sometime in the past week, the Star-Tribune reported, he marched investigators to a farm in Paynesville, 30 miles south of St. Joseph, where they found the skeleton of an 11-year-old boy. They confirmed via dental records that the remains were those of Jacob; DNA testing is pending.

Authorities have not said what, if any, charges they would bring against Heinrich. In a statement, the Stearns County Sheriff’s Office said it would provide more details later this week.

Heinrich, a convicted sex offender, lived with his father in Paynesville. He has committed sex crimes against children in the past, according to the Star-Tribune.

Danny Heinrich. (Sherburne County Sheriff’s Office via AP )

Heinrich was arrested last year on federal child pornography charges. According to the Star-Tribune, “when authorities arrived at Heinrich’s house with a search warrant, he described himself as ‘a dirty old man’ but denied creating pornography or sharing it with anyone, according to a federal agent who testified in court.”

According to the newspaper, investigators found 19 three-ring binders full of child pornography, some featuring kids as young as 12. There was more child pornography on his computer. For a year after being arrested, he had denied knowledge of Jacob’s disappearance.