Who does Steve Jurgenson ask Stevie and Susan Carol to give statements to in Chapter 18? Why?

Jurgenson takes Stevie and Susan Carol to Special Agent Applebaum from the FBI, so they can confirm Jurgenson's story. Jurgenson tells Stevie and Susan Carol that the dean had also been calling the president of MUS, Earl Koheen, who Jurgenson says is the originator of the blackmailing plan.