Updated

More than two decades after 12-year-old Johnny Gosch disappeared while on his newspaper route and became one of the first missing children to be put on a milk carton, a potential new clue to his fate was literally dropped on his mother's doorstep.

Inside an unmarked package more than two weeks ago were two photographs that Noreen Gosch says show her son bound and gagged.

"When I saw them I could barely breathe," she said.

One black-and-white shot shows Johnny on a bed, wearing the same sweat pants he had on when he vanished, the boy's mother says. She says the other photo, this one color, shows him in a similar pose with two unidentified boys who are also bound and gagged.

Investigators with Iowa's Department of Criminal Investigation said they are analyzing the photos, trying to determine their authenticity, where they might have come from, and whether there are any fingerprints or DNA that can be lifted from them.

"They don't appear to be doctored. It's the source of the photographs that we're looking at. Are they connected to any other cases? And is it Johnny Gosch in the photos?" said John Quinn, agent in charge of the case for the DCI.

"It's a priority. Absolutely it is," Quinn said. "Were taking it very seriously. We have some promising leads in regards to information from the photographs."

The freckle-faced, gap-toothed boy was last seen before daybreak on Sept. 5, 1982. His wagon, filled with copies of the Sunday paper, was discovered near his West Des Moines home, but there have been few solid clues since then. Police have said they believe he was abducted.

Coming just a year after the highly publicized abduction of 6-year-old Adam Walsh in Florida, the disappearance of Johnny Gosch was seen as a similar watershed event. If it can happen in heartland Iowa, parents felt, it can happen anywhere.

The case contributed to what some regard as an obsessive fear of children being abducted by strangers. Most kidnappings are committed by family members, not strangers, according to studies by the U.S. Justice Department.

"Once every child becomes vulnerable, then it can become an obsession among all parents because it can happen to your child," said Paula S. Fass, a professor at the University of California at Berkeley and author of "Kidnapped: Child Abduction in America." "The fear that parents now walk around with is unlike anything that we've experienced in the past."

Noreen Gosch said she believes her son was taken by child pornographers and forced into sexual slavery.

She has told authorities that her son showed up at her door in 1997 with a stranger. She said he told her he feared for his life and wouldn't give details about himself. No witnesses have corroborated her account. Johnny's father, now divorced from Gosch, has said he is not sure the visit ever occurred.

Gosch said she also believes her son's disappearance is connected with the apparent kidnapping of a Des Moines boy, Eugene Martin, who vanished two years after Johnny. Like Johnny, Eugene was on his paper route in the early morning. Authorities say they are unsure if the two cases are connected.

The National Center for Missing Children said it is examining the other boys in the photograph and trying to match them against its database of missing children.

"These kids have parents someplace," Gosch said. "I'm sure they feel the same way I did. Hopefully we can do some good and give these parents some peace."

Gosch, assistant manager at a Des Moines-area store, said she believes the pictures are real. But as for why they have surfaced now, she said: "I have no idea. I'm as shocked as anyone else."

"I kept looking at Johnny's little face in the black-and-white photographs and I kept wondering if he was sitting there thinking, `Are they going to kill me? Will they find me?"' she said. "It really is so hard. Every time I look at them I practically get sick."