Federal prosecutors say a convicted child sex offender downloaded more than 3,500 images of child pornography.
Keith Clack is charged with knowingly receiving child porn.
The 41-year-old Atlantic City man made his initial court appearance Friday and will remain in custody. He's represented by a federal public defender who, under office policy, doesn't comment on cases.
Prosecutors say Clack used various electronic devices to access the images, which included infants and toddlers being sexually abused.
Clack was previously convicted of sexually assaulting a youth and child endangerment, so he would face enhanced penalties if convicted. Prosecutors say he would have to serve at least 15 years in prison and as much as 40 years.