[2] His loving, but elderly, adoptive parents died shortly before Dr. Sweets began working with Booth and Brennan, leaving him without a family.

[5] This has led some members of the team to doubt his degrees' validity, and Sweets has admitted to Brennan that he earned money for graduate school by teaching psychological techniques to car salesmen — a fact that he is not proud of.

[7] Like his colleague FBI agent Seeley Booth, he is based at the J. Edgar Hoover Building and can be usually found in his consultation room.

He occasionally accompanies Booth to interview victims' family members or analyze a crime scene for insight into a suspect.

Sweets appears to be formally trained as a psychoanalytic psychologist, often referencing Freudian theories and approaches, even describing the psychosexual stages of childhood development to Booth.

[12] Ironically, Dr. Wyatt notes that "Freud has been largely discredited" in "Mayhem on a Cross", but still shows a great amount of respect and support towards Sweets.

He was also the first to correctly deduce murderer Christopher Pelant's real motives after the Jeffersonian team kept hitting dead ends with the physical evidence.

He becomes closer to Booth and Brennan after a moment during "Mayhem on a Cross" when they share their traumatic pasts, eventually becoming a surrogate family and hiding their emotional bond with banter.

Sweets has also started appearing more frequently in the field; notably, undercover as Angela's aspiring-fireman-husband-with-a-bad-back, to gain information on a suspect without a warrant.

In the episode "Mayhem on a Cross", Dr. Sweets received a review by Dr. Gordon Wyatt of his book on the relationship between Booth and Brennan.

Dr. Wyatt explains he feels Booth and Brennan are much more similar than Sweets understands and that one of the two is, in fact, aware of the underlying sexual tension between them and struggles with it daily.

During the time frame between Seasons 5 and 6 Sweets takes a sabbatical from the FBI while Dr. Brennan and Daisy went to the Maluku Islands, Booth was deployed to Afghanistan and Angela and Hodgins traveled to Paris.

After Booth kills Pelant, Sweets returns permanently, only to find that the department has acquired a new computerized profiling system called VAL and linked it to Dr. Camille Saroyan's office at the Jeffersonian.

Although Sweets wishes to reveal this to Brennan and Booth, Zack invokes patient confidentiality, knowing that he would be prosecuted as an accessory to murder and believes that he would not fare well in prison.

Throughout the fourth season, the two develop a father/son relationship, something that is especially obvious when Sweets turns to Booth for advice about his girlfriend in "The Cinderella in the Cardboard".

[2] Prior to this, Sweets has made his own attempts to develop a friendship with Brennan, even asking on one occasion to call her "Bones" after she protects him from an attacker, although his request is promptly denied as the moniker was reserved exclusively for Booth.

[22] Later on, during "The Night in the Bones Museum", Brennan agrees to rehire Daisy when Sweets says he would take it as a personal favor, possibly as a result of her affection for him.

There is, however, one aspect of Sweets' psychological training that Brennan seems to continually respect: his ability to discern lies, acknowledging that physical reactions can indicate dishonesty.

He stayed with them for several months after he broke up with Daisy and when he was about to move into his new apartment, Brennan expressed her sadness that Sweets would no longer be there to help babysit Christine or share his recipes.

He tells Sweets that he has a good heart and a genuine desire to help others that makes psychology his true calling, something that Gordon himself does not have.

At the end of "The Skull in the Sculpture", Sweets insists on personally breaking the news to her when Cam decides to fire her, telling Daisy that the upside of it is that they no longer must be discreet about their relationship.

Though both are excited about this at first, after talking with both Angela and Booth, Sweets begins to second-guess living with Daisy, realizing that, though she wants to eventually get married, and even someday start a family; all the things he wasn't entirely sure about yet.

Lance Sweets is brought into the series early in the third season ("The Secret in the Soil") as a psychologist to Seeley Booth and Temperance Brennan.

Sweets' presence provides a bit of comic relief, as he is often the target of insults from both his clients, though they do show sympathy for him on occasion.

His youth (according to Angela, Sweets needs to show his ID at bars to drink) and inexperience with police work also prove to be a challenge for him in the series, as many don't take him seriously, although his psychological analysis of Booth and Brennan is typically quite accurate.

Sweets is characterized as extremely intelligent and he has often been able to provide much-needed insight into a case when the Jeffersonian team hit a dead end with physical evidence.

[19] He is musically-inclined and plays the piano (as does actor John Francis Daley);[25] in during the time frame between Seasons 5 and 6 he takes a sabbatical when Booth, Brennan, Angela, Hodgins and Daisy leave Washington DC for a year and becomes a freelance pianist.

[26] In the season 4 finale, "The End in the Beginning", he is presented as a bartender ("practically a psychologist") and the lead singer and keyboardist of a band called "Gormogon", a reference to a character in a previous story arc.

After Booth and Bones seek to keep a delirious and fading Sweets from expiring, he finally succumbs to his wounds and dies as an ambulance is heard arriving in the background.

It's..."[28] Sweets was determined to have been killed by a Navy SEAL named Kenneth Emory, who was acting on the orders of Glen Durant — aka the President of the Shadow Government.