Back-story Spoilers!!!!!! The Mcalister Clan made the trip from Ireland with the
Janes and other important clans. The clans where mystics and masters of
the dark arts. There was much division among the clans related to the
luciferian religion. The religion it self is not considered bad but
rather dangerous if used by the uninitiated. The Mcalisters began using
there skills like parlor tricks early in the 19th century until the
great rift. It was the council of the elders that the Clan was banned
from the practice of black magic. Mcalisters practiced in secret until
the gifted RED JOHN appeared. Mcalister is the figurative embodiment of
the great dragon with the Blake society being the true force of the
cult. RED JOHN merely practiced human sacrifices as part of his
luciferian religion. RJ took offense when Jane spoke callously of his
religion and sacrificed his wife and child as act of contrition and
vengeance. The FBI has been looking into child and adult abduction and
sacrifices cases since the 60's but very closely since 80's. The Red
John ascended master period. Stiles was practicing the white version and
RJ the black.

I try to make it short, I leave the thinking to you guys.
I know Kirkland is dead, but check this out!
Kirkland's Brother is RedJohn.
He is Bob's "twin" brother and he might look exactly like him (if they are identical)
Rj
became an alchoholic, then he joined visualise, worked in a visuallise farm, changed his attitude
and started his own group (that's why Bret Stiles knows so much about
him),
Bob only thinks his brother is dead, and that's what Rj wanted Bob to think, because Bob abondaned him. this way Rj can have his brother's identity as well.
Bob Kirkland Fits the RedJohn profiel Perfectly, not too old or too young, and a bit scary.I also think some of the footage
that we saw of him during the Mentalist seasons were actually footages
of his brother.
(keep in mind that Bruno Heller said one of the seven suspects is definitely RedJohn, and this theory covers that too)
just a theory guys, you be the judge ;)

eventhough mcallister wasn't a bad choice i wish it was kirkland simply because he was by far the most perfect candidate for RJ he was creepy always seemed to be hiding something smart enoguh not to fall for jane's mind tricks when he held him for torture and didnt seem to be afraid from patrick at all as he simply said yes when jane asked if homelandsecurity has been watching him.