Matthew T. Williams, 43, was seized during a raid of his Westfield apartment on Wednesday, Nov. 1.
Homeland Security Investigations agents from Newark reported more than 40 child sexual abuse videos found on a drive attached to Williams's computer that was pulling more from the Internet when they arrived.
Williams was living in New York State when he was previously convicted of sexual abuse involving a minor in the town of Virgil near Ithaca, according to an HSI complaint filed in U.S. District Court in Newark.
Undercover cyber sleuths patrolling the Internet early this year found Williams's computer sharing particular files that bore what are known as "hash values," the complaint says.
A "hash value" is a unique series of numbers and letters that remain with any and every image even if it's copied or shared in any way. Call it digital DNA.
An automated process known as “hash matching” points investigators to files shared on peer-to-peer networks that match hash values in a massive directory of previously reported child pornography.
The database is maintained by the Alexandria VA-based National Center for Missing and Exploited Children, which reported reaching roughly 7.4 million total hash values last year.
Federal agents can zoom through the images in a blink and detect child pornography without even having to view them. Facebook, Google and other social media platforms also have access to the file numbers and can alert authorities whenever any turn up.
Videos shared from Williams's IP address included "multiple visual depictions of prepubescent children engaged in sexual acts alone and with adults," the HSI complaint filed in Newark says.
One of the videos, which ran for nearly a half hour, depicts an underage girl exposing her genitals and masturbating, the complaint says.
Another "presents a prepubescent minor female performing oral sex on an adult male," it says.
Agents who arrested Williams at his Central Avenue apartment this week also seized his laptop. along with an external drive that they said not only contained dozens of abusive videos but was also in the process of downloading more.
Williams, who lives alone, told the agents that no one else had access to the laptop, the complaint says.
They charged him with possession of child pornography, U.S. Attorney Philip R. Sellinger said. A federal magistrate judge in Newark later released Williams on $100,000 unsecured bond pending trial, the U.S. attorney said.
The arrest "should serve as a message to all predators who hide in virtual spaces that our special agents have ways to find them and bring them to justice,” said Robert Kurtz, the HSI Newark acting special agent in charge.
Sellinger credited Kurtz's staff for making the case against Williams and also thanked the U.S. Postal Inspection Service and the Union County Prosecutor's Office "for their support in the investigation."
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