A statement from Springfield's U.S. attorney's office followed a Wednesday detention hearing in Urbana for 28-year-old Brendt Christensen. A judge ordered he remain jailed because he's potentially dangerous.
Prosecutors said 26-year-old Yingying Zhang fought Christensen as he abducted her June 9. Prosecutors say Christensen also spoke about what makes an ideal victim. Prosecutors didn't explain to whom Christensen made the comments.
Agents arrested him Friday. Attendees at Thursday's vigil also walked to the street where Zhang was last seen. Authorities believe Zhang is dead, though her body hasn't been found.
A message left for Christensen's lawyer wasn't returned.