A Massachusetts man with a prior child pornography conviction has admitted illegally importing radioactive material from Russia and distributing it to buyers across the United States, federal authorities said.
Jacob D. Miller, 44, pleaded guilty to importing plutonium from Russia and having it shipped to his home in South Hadley, where he operated a business called “Collect The Periodic Table,” the US Attorney’s Office for the District of Massachusetts announced Monday.
Miller was convicted in February 2004 of possessing child pornography and an explosive device. He received a two-and-a-half-year prison sentence followed by 10 years of probation, prosecutors said.
After his release, Miller launched Collect The Periodic Table, selling samples of chemical elements that included radioactive plutonium and the highly poisonous metal thallium.
Officials said he marketed the materials both through his own company and via Bonanza, an online third-party marketplace.
Between Dec. 30, 2020, and March 31, 2025, Miller sold plutonium to about 67 customers, prosecutors said. In some cases, he sent the radioactive substance through the US mail.
Federal authorities also said he sold thallium to 71 customers located throughout the country.
Plutonium is a radioactive, silver-colored metal that can be used in nuclear weapons. It can be fatal if inhaled, swallowed, or introduced into the body through an open wound. Thallium, meanwhile, is an odorless, tasteless and slow-acting heavy metal known for its extreme toxicity.
When investigators searched Miller’s home in April 2025, they found a box containing bottles of explosive powder, numerous rounds of ammunition and six firearms he was prohibited from possessing, prosecutors said.
Authorities also found additional child sexual abuse material on Miller’s laptop and cellphone. Court records indicate he had accessed the material as recently as the day before investigators executed the search warrant.
A federal grand jury indicted Miller on April 17, and court filings state that he has remained in custody since his arrest that month.
Miller pleaded guilty to multiple charges, including being a felon in possession of ammunition, being a felon in possession of explosive materials, importing nuclear material without legal authorization, mailing hazardous materials and possessing child pornography.
US District Court Judge Mark Mastroianni is scheduled to sentence Miller on Jan. 21, 2027.