A 44-year-old Mankato man is facing 13 child pornography-related charges after the Federal Bureau of Investigation contacted Mankato Police, saying they had linked the download of more than 4,000 files of suspected child pornography to an IP address at the home of Marcus Rosenstein.

A federal search warrant was issued, and the FBI says an analysis of the files seized showed Rosenstein’s desktop computer contained nearly 8,000 images of child erotica and child pornography. Agents also found a nearly hour-long video of suspected child pornography.

Rosenstein was present during the search and the criminal complaint shows he admitted that the FBI would find child porn during their search. He claimed he first encountered child pornography when he “ran across a disturbing image” on 4Chan and reported it about ten years ago. Rosenstein claimed that he attempted to find more images to report to the FBI but never heard back from agents and he then slowly started to develop an interest in child pornography.

Agents say Rosenstein admitted that he is interested in viewing images of females ranging in age from 7 to 25 years old and that he has been downloading and collecting child pornography for approximately five years.