One of three things is possible now ;-

1) RJ returns,the show does give us little hints of such a thing like............Jane saying he will paint the town "Red". When Rigsby was advancing into that dark area there was a tint of Red light across his face. But if this was RJ,why didn't he draw his smiley face?

2) Missing members of BA are out for revenge.

3) A new villan named Blue George might make his debut.

PS: Sherlock fans,stop posting about Sherlock on a Mentalist discussion page.