At around 15:30 the photo mugshots of Stephen Atwood, Paul Ballard, and Carl Mittendorf are shown on the case board. But Mittendorf isn't introduced as a person of interest until a minute later and it's with just a black and white printout of his mugshots.
The kidnappers go after confidential Federal Reserve data. When asked specifically what they are after the agent monitoring the break-in says that they are after the prime rate. While it ties into the episode title of Prime suspect and the episodes theme of prime numbers, the Prime Rate is NOT one of the rates that is set by the Fed.