The professor is Charlie Eppes played by David Krumholtz (The Santa Clause, 10 Things I Hate About You), the FBI agent brother is Don Eppes played by Rob Morrow (Northern Exposure, Quiz Show). Hope that helps. And for the record... I want Peter back on Numb3rs I can't wait til his time ends on 24 so we can have Larry Fleinhart and all his quirkiness back. Including his love of white food.

Does anybody know Peter's costar on Numb3rs? The one who is the proffesor who has the brother who is a cop? Not trying to get off the subject of Peter, who is an awesome actor, it's just bugging me that I don't know who he is.