The investigation, nicknamed Operation Hamlet, began in Denmark and Germany and led investigators to just outside California's capital. The international effort yielded more than one million images of child porn, authorities reported.
At the center of the investigation carried out by the Bureau of Immigration and Customs Enforcement was a doctor named Lloyd Alan Emmerson, who according to authorities, functioned as the kingpin to all the suspects in the case and was charged with distributing massive amounts of child porn images from his office in Clovis.
Emmerson's arrest happened in 2002 after several European suspects were taken into custody and mentioned that they had gotten their content from a U.S.-based contact.
Investigators discovered more than 400,000 encrypted files containing child pornography on Emmerson's harddrive, although according to the Fresno Bee, it took three forensic examiners 11 months and more than 5,000 hours to decrypt the content.
Soon after, Emmerson and more than a dozen child porn suspects were indicted by a federal grand jury in Fresno, the Fresno Bee reports. Emmerson pleaded not guilty and will be tried in April 2004. Some of the suspects in the case have pleaded guilty and have been sentenced to between 10 and 50 years, according to the case's lead prosecutor.
"These arrests indicate how much work it takes to build a case against child pornographers even with over 400,000 child pornography images," Joan Irvine, executive director of Adult sites Against Child Pornography (ASACP), told XBiz. "This demonstrates why it is so important to send reports to law enforcement agencies or to ASACP(https://www.asacp.org/reportsite.html) and not discuss the details on the boards."
The investigation into Emmerson's involvement in the child porn ring led to the Friday arrest of Michael Ferguson of Tennessee, who is being accused of conspiring with the chiropractor via email to produce child pornography material with underage girls.
Ferguson used the pen name 'Ratboy,' according to the Fresno Bee. Materials were discovered in his home that suggest he played a major role in producing child porn content for Emmerson's porn ring.
Ferguson is facing federal charges in Tennessee as well as state charges in California.
Starting in the first quarter 2004, ASACP will begin to complement its existing human reviewer process by introducing Image Spiders which will retrieve all images from suspected child pornography websites.
The human reviewers will analyze each image to determine if it is child porn. Images that are "red flagged" are then hashed using MD5 and SHA1. Data values such as the URL of the image will be inserted into the database and the images permanently deleted.
According to ASACP, the MD5 and SHA1 hash values and Image Diff of a known child pornography image identify the image like a fingerprint. As the Image Spiders are downloading more images from suspected child pornography websites, each image can first be "scrubbed" against the master database to remove duplicates or to flag where a known child porn image has been found on another website.
