By Jessica Michele Herring (staff@latinospost.com) | First Posted: Nov 01, 2013 02:41 PM EDT

A new clue was revealed that could lead the team closer to Red John on the latest episode of "The Mentalist."

In the episode, Jane (Simon Baker) learned from a private eye (guest star Beth Riesgraf), who was hired and stabbed by Red John, that the infamous killer has a tattoo of three dots on his shoulder.

Executive Producer Eoghan Mahony, who wrote the episode "The Red Tattoo," told TVLine that that the tattoo clue will not mislead Jane.

"That is a legit clue, and it is a big deal. Now Jane's got his leverage," Mahony said.

Now that Jane has the clue, he needs to figure out how to use it. As to how he'll do that, Mahony said, "You're just going to have to watch the next episode, but you're going to enjoy it a lot. Jane's going to tell the team what he's found, and they're going to ask exactly that: How do we figure out [who has the tattoo]? But luckily you've got Patrick Jane to find the best way to make that work."

This past episode also suggested that Sheriff McAllister (Xander Berkeley) is afraid of pigeons and Ray Haffner (Reed Diamond) has a case of arachnophobia. But it is not certain that these revelations mean Red John has a phobia.

Mahony explained why they decided to spread the clues over a number of episodes. "Whoever Red John is, we know that he is an incredibly brilliant mind. He's a psychopath but a brilliant one, so he's not to going to be easy to find," Mahony said.

"So how can we, using what tiny crumbs of information we have, force him out into the open? We saw that McAllister might have a fear of heights but clearly he doesn't," he explained. "And if you throw a bird into my face I'm probably going to scream, so is that reaction a phobia or just a reaction to having a bird fly in your face? That's the challenge Jane and the team are faced with."

The upcoming episode, called "Fire & Brimstone," "moves the story forward in a way that going to be both surprising and will keep you on the edge of your seat," Mahony teased. "It's a good one."

The synopsis for the episode reads: "With the final clue in hand, Jane attempts to gather the remaining Red John suspects in one place in hopes of finally revealing his identity." 

Watch the promo for "Fire & Brimstone" below, which airs Sunday, Nov. 3 at 10:30-11:30 p.m. ET.