Beginning in January, "each will fall under suspicion and be looked at during the course of various episodes," teases executive producer Tom Szentgyorgyi. The intense probing will uncover secrets about the team and threaten to destroy the Rigsby/Cho/Van Pelt dynamic.
Will one of the three be found guilty of the murder — and have ties to Red John? "I can neither confirm nor deny — I can't even approach that," says Szentgyorgyi. But he does reveal, "In 2011, the investigation will take a startling turn and the team will change dramatically."

Source: TV Guide