Todd Blanche, the acting attorney general, said on Monday that investigators were working to determine if the suspect had any connections to left-wing activists.

Federal agents outside Delaney Hall Detention Facility in Newark in June. Immigration and Customs Enforcement has curbed access to its detention centers and required seven days’ notice for lawmakers seeking entry.

Peter Navarro’s sentencing hearing was scheduled for January. Each count carries a maximum of one year in prison and a fine of up to $100,000.