The "mentalist" to which the title refers is Patrick Jane, (played by Simon Baker), who as an independent consultant to the California Bureau of Investigation (CBI) advises.Jane has a remarkable gift to solve crimes by using his razor-sharp observation skills. Despite that Patrick following to the protocols, he is rated by his peers. Patrick previously worked in television as a medium, but now he admits that he has assumed that psychic abilities.
Teresa Lisbon (Robin Tunney) is the accompanist for Patrick Jane and his boss. They know he has talent and that his methods often impact. Teresa is always determined to solve the crime, with or without Patrick. In the team of Lisbon also work the agents Kaan Cho (Tim Kang, also in Third Watch), Wayne Rigsby (Owain Yeoman, also inThe Nine and Generation Kill) and Grace Van Pelt (Amanda Righetti, also in The O.C.).
The series also introduces the background story of Patrick Jane. His wife and daughter are murdered by the 5 years before the series began serial killer named Red John.Immediate cause for these murders was a tv broadcast in which Patrick, when challenged, Red John still as medium. Patrick feels responsible for the event and is tormented by guilt. This is expressed in headaches and insomnia. Red John appears regularly in several episodes and Patrick is eager to deal with him, and that is also one of the reasons for him to be able to work for the CBI. That the story of Red John as a red thread through the events worth 10 euros, makes it plausible that in the title of almost every episode the word "red" is processed.
On 27 March 2013 CBS made known that The Mentalist will also get a sixth season. This season started on september 29, 2013.  In this season one will reveal the identity of Red John . Season 6 is also divided into two parts: the first part (episode 1-8) is about how afrekende with Red John Patrick for good. Starting from episode 9 plays the story takes off and starts 2 years later Patrick to be working now for the FBI.
The sign that the serial killer Red John leaves behind at the crime scene.*Patrick Jane (Simon Baker) is an independent consultant with the California Bureau of Investigation ' (CBI). He previously earned a living as a professional (and fraudulent) tv-medium Red John , until his daughter and wife killed in retaliation for his mocking television appearance. He is known for his razor-sharp observations and wants to use his skills to solve murder cases, even though he has paint rules. His contribution is very much appreciated by his colleagues. Also chef Teresa Lisbon is very happy with the work Jane does, but annoys itself to its sense of theatricality, vigilantism and his urge to always to look up the limits of the permissible. Despite this, Jane close friendships with his colleagues. Although generally playful and brilliant, he shows a much darker side concerning Red John, the serial killer who murdered his family.When he will meet Red John, he is willing to sacrifice everything, and he does not to catch him and to kill him. In season 3-eight years after the death of his wife and daughter-Patrick comes face to face with a man who makes himself known as Red John. During his showdown he shoots the man down and he is arrested. Later it turns out this is not the real Red John and Jane goes further with its quest for Red John. "Red John" (season 6, episode 8) Patrick finally comes to know who Red John is his arch-enemy kills and eventually with his life can go on. 2 years later, Patrick returns back when the FBI offers him a new job.
- Senior Special Agent Teresa Lisbon (Robin Tunney) is the leader of the team whose also Jane is a part of. Though Patrick often annoys her with his unusual behavior, she sees him as a valuable member of the team and she nevertheless agree some of his most unusual theories. Her mother was killed in a car accident, in which alcohol was in the game. She has a trust relationship with the sole team member Patrick Jane and knows the details of his past. Often, they work well together, but his attitude often causes problems for her with the local law enforcement. Her team was responsible for the case of Red John until he was unmasked and killed in "Red John" (season 6, episode 8). It was then abolished and CBI was Teresa a sheriff in a small town. She starts to work for the FBI back later with Jane.
- Senior Special Agent Kimball Cho (Tim Kang) has a dry and deadpan humor. He usually follows the mindset of Jane, because he has respect for his talents. He is often the one who can't see through the tricks of Patrick (then told Patrick to Van Pelt that he with his gift could move without a straw across the table to touch said Cho simply: "he blew against it"). He has been a member of a street gang, the Avon Park playboys. Prior to joining the CBI came, he still served for the United States Army's Special Forces.2 years after the opdoeking of the CBI Cho now works for the FBI.
- Special Agent Wayne Rigsby (Owain Yeoman) (season 1-6) is an absolute team player. He's the macho of the CBI team, who acts first and then thinks, and has a crush on Van Pelt. Initially he gave not admitting he was in love with her because this is against the rules, but in the end he gave it anyway and they came ever closer to each other. Their relationship eventually became widely known and the chef Madeleine Hightower gave them an ultimatum: either their career end at the CBI or their relationship. They decided to stop the romance. In season 6 marries Rigsby with Grace. After Red John is finally unmasked in "Red John" (season 6, episode 8) decided to start their own security company Rigsby and Grace. 2 years later they have a daughter called Maddy.
- Special Agent Grace Van Pelt (Amanda Righetti) (season 1-6) is the rookie in the CBI team, but equally competent and reliable as the others. She believes in higher forces and thinks Patrick Jane really possesses paranormal gifts. Jane itself is an absolute atheist and that provides the necessary tension between the two. After they had finished she went with Rigsby the romance a relationship with Craig O'Laughlin, a Special Agent in Charge at the FBI, who was shot as one of the Red Johns henchmen in the finale of season 3. In season 6 marries Grace with Rigsby. After Red John is finally unmasked in "Red John" (season 6, episode 8) decided to start their own security company Rigsby and Grace. 2 years later they have a daughter called Maddy.
- Special Agent Kim Fischer (Emily Swallow) (season 6) is an intelligent and attractive FBI Special Agent from Dallas who is not afraid to stand up for herself. She appears for the first time in "My Blue Heaven" (season 6, Episode 9) and tries to convince Patrick to return.
- Special Agent Dennis Abbott (Rockmond Dunbar) (season 6) is an FBI Special Agent who sent to strengthen the team of Lisbon in their quest for Red John. He is particularly calm when he is facing a crisis but he is not someone you want to make angry. He has fought in the war of Iraq. He appears for the first time in "The Great Red Dragon" (season 6, episode 7).
- Special Agent Jason Wylie (Joe Adler) (season 7) is an FBI computer expert that becomes a member of Jane's team in season 6.
- There has got to be said that The Mentalist is a rip-off (imitation) of the series Psych about Shawn Spencer who is the man who had his observation skills and attention to detail solves crimes, but pretending to be psychic and solves the issues with his gift. Psych began in 2006, and The Mentalist began in 2008.