In a little white house on a quiet, tree-lined street in Northfield, a man who goes by the name "Kahn Amore" helped hundreds of thousands of child porn patrons around the world view images and videos of sexually abused children, federal officials say.

Ernst O. Luposchainsky III now sits in a California cell, indicted on federal charges of distributing child pornography. In court documents, officials say the 55-year-old admitted that his website -- Hypatia-lovers.com -- created an image- and video-sharing haven for people sexually attracted to children. Authorities busted Luposchainsky in September, after intercepting a letter addressed to him from Melbourne, Australia, from someone who frequented his website.

The Minnesota office of Immigration and Customs Enforcement (ICE) currently has 35 open child pornography investigations and has conducted 126 such investigations over the past three years.

Every week, investigators chase child porn purveyors from around the world to stop the smut and rescue their young victims. They monitor broadband frequencies and pore through hard drives to uncover clues that often lead to networks of cyber-communicating offenders, officials said.

"Child pornographers are collectors. And just like any other collector, it's no fun unless you can share with other collectors," said Claude Arnold, special agent in charge of criminal investigations for ICE in Minnesota. "These sickos want to share with their buddies."

A flood of pictures

Since 2002, officials have analyzed more than 28 million child porn images in hopes of finding both the criminals and the victims, said Michelle Collins, executive director of the Exploited Children Division at the National Center for Missing and Exploited Children.

The pace is accelerating -- more than 8 million images have been intercepted since the start of the year, Collins said.

Many are older pictures and videos that are recycled or doctored with Photoshop-type programs, but Collins said federal agents are on the watch for new images and new victims.

In 2002, Collins said, law enforcement had identified 25 of the children whose images were frequently seen on the Internet. As of today, that number is more than 2,600. What that means, she said, is that those children no longer are being actively photographed -- although their images can circulate on the Web for years.

Arnold said that because so many images either originate overseas or are distributed around the globe, ICE is heavily involved in child porn investigations as part of its Operation Predator. He said he cannot comment on an ongoing case like Luposchainsky's.

Arnold recalled a 2005 case in which investigators traced child porn images from Atlanta to a Burnsville basement. In one of 78 child porn images on an Atlanta computer, investigators could make out a Brownie uniform. That uniform eventually led to a Minnesota troop member and, based on that, the victims were identified.

Bruce W. Betcher of Burnsville was sentenced in May 2007 to 750 years in prison for manufacturing, receiving and possessing child pornography.

"Very often, in these cases, one thing can lead to another," Arnold said.

On any street

On July 23, 2008, ICE agents searched the little house on W. 8th Street in Northfield. A National Guard HAZMAT team wearing oxygen masks removed what were believed to be hazardous chemicals. Neighbors said a helicopter hovered overhead and Luposchainsky and his parents stood in the back yard. No one was arrested then.

In a recently unsealed search warrant affidavit, an ICE agent said that authorities had received information from a resident of Imperial County, Calif., in June 2008, that an individual using the name Khan Amore was distributing child pornography on the website Hypatia-lovers.com.

Agents said they traced the site to a Web account owned by Luposchainsky, searched the house and found hundreds of thousands of pornographic videos and images, including some of children having sex with adult males. Luposchainsky admitted then he is sexually attracted to young girls, they said.

The images apparently were removed from the site sometime later, prompting the letter from Melbourne in September 2009, asking where they were.

Luposchainsky was arrested and appeared before U.S. Magistrate Judge Arthur Boylan in St. Paul on Sept. 4. Boylan ordered Luposchainsky to be held without bail and transferred to the U.S. District Court in San Diego.

During that hearing, Boylan wrote, "the defendant had appeared previously to have taken photographs of at least one known child and 'photoshopped' the head of the child onto the sexually explicit image of another child, thereby creating a new, sexually explicit image."

He continued: "There was evidence to indicate that the defendant had previously taken or obtained possession of photographs of children taken by a hidden photographer in a residential area consistent with the area in which the defendant lives."

In an odd twist, he added, "Finally, there was evidence that the defendant had possession of chemicals which, in certain combinations, could be used as weapons or poison."

A visit to Northfield

There is a small city park, with a playground, less than a block from Luposchainsky's house. There are neighbors nearby who have young children. Several neighbors declined to talk on the record about the thin, middle-aged man who lived with his elderly parents and posted multiple musings on Internet message boards about the diameter of machine screws, the effects of elevation on atmospheric pressure, taking photographs at night and what to do if your parachute doesn't open.

One neighbor said Luposchainsky spent most of his time in the house, although she thinks he's had a collection of odd jobs over the years.

Luposchainsky's father recently answered the door at their home, but declined to talk about his son.

Luposchainsky's attorney, Stephen White, confirmed that his client is being held in a California jail, but he would not say where. Luposchainsky has pleaded not guilty to the charges against him. But he has waived his right to press for his release on bail.

Beyond that, the attorney would say nothing more.

"I probably have to hold off on any other comment," he said.

James Walsh • 612-673-7428