'That plump, annoying FBI agent who appeared once in season five? No way!' I hear you say.

That's what I thought too at first. Let me explain...I'll start with a quote by Bruno Heller:

"Red John is like Waldo, lurking in the background"

Now most people assumed that Reede Smith only appeared in the season five opener.

Wrong!

In episode 5x18 guess who I saw in the BACKGROUND about halfway through the episode? Reede Smith

I'll have to give it to Bruno Heller, because he placed Reede Smith in a position where he was too far away to be easily noticed, yet possible to be picked up by the subconscious mind. But I, being observant, was able to spot him.

This intrigued me to investigate further to see if this was the only episode Reede appeared in. I discovered that he also appeared in 5x06, and - briefly - in 5x16.

Virtually unnoticeable to the average watcher of the series, Reede Smith - aka Red John - is, as Heller correctly put, "like Waldo". You have to look for him to find him.

Of course, this is no conclusive proof that Reede Smith IS Red John, but it is certainly strong evidence that might suggest so.