The cast of “Criminal Minds”

For as long as there have been people, we have been committing crimes against one another. Depictions of criminal behavior can be seen in literature as early as "The Three Apples" tale from "One Thousand and One Nights," originating some time in the eighth or ninth century. Early examples had little in the way of what we now consider detective work, such as collecting evidence or determining motives.

In the 19th century, crime fiction grew up a bit and became its own genre, paving the way for the plethora of crime books, movies and television shows that exist today. One notable contemporary example is "Criminal Minds," which has entered its 10th season and will air a new episode Wednesday, Nov. 12, on CBS.

Unlike other popular procedural dramas, "Criminal Minds" doesn't necessarily focus on solving one specific crime. Rather, the FBI's Behavioral Analysis Unit (BAU) works out of its Quantico, Va., base and is fed notable cases from around the country. These cases generally involve serial killers, although serial arsonists, rapists and kidnappers have also been featured. The BAU then uses its expertise to analyze the unknown subject's (UnSub) crimes and known behavior in order to form a profile with which to narrow down suspects.

Over the 10 seasons that it has aired, "Criminal Minds" has undergone various cast changes. Most recently, and perhaps most notably, Jennifer Love Hewitt ("The Client List") stepped into the shoes of Kate Callahan. Callahan has been with the FBI in various roles for eight years, and in her first appearance in the season 10 premiere, she is undercover, taking down pedophiles before joining the BAU.

"I wasn’t quite sure at first if I was going to be a newbie who hadn’t done this before," Hewitt said in an "Entertainment Weekly" interview. "When they told me about her, I was really excited that she comes with her own background and talent. She had met the BAU team before in an interesting way, which they talk about in my first episode."

Hewitt's casting caused a ruckus on the Internet, with fans taking to Twitter and other social media platforms to express both outrage and delight at the appointment. Some see Callahan as a replacement for fan favorite Emily Prentiss (Paget Brewster, "Dan Vs."), although Prentiss was written out of the show at the end of season 7. Her actual replacement was Alex Blake, played by Jeanne Triplehorn ("Basic Instinct," 1992), who joined the cast for two seasons. Despite Brewster's lack of desire to return to "Criminal Minds," fans are still calling for her character to be reinstated.

This is a departure from Hewitt's typical roles. Her breakout came on the television series "Party of Five" and was followed up by roles in various films such as "I Know What You Did Last Summer" (1997) and "The Adventure of Tom Thumb & Thumbelina" (2002). Unlike many Hollywood stars, Hewitt has also maintained a presence on the small screen. Perhaps her best known role was as Melinda Gordon in "Ghost Whisperer," in which she helped spirits trapped in her small town for five seasons.

Jennifer Love Hewitt and Matthew Gray Gubler star in “Criminal Minds”

While both that and her new role involve investigations, Hewitt was much more sympathetic in "Ghost Whisperer," often empathizing with the unfortunates she aided. Callahan, on the other hand, holds no such feelings for the UnSubs she tracks down in "Criminal Minds." As Hewitt puts it, "[Callahan] has absolutely no sensitivity for these people just because she believes in the right in people, doing things the right way and not hurting other people."

Hewitt is stepping into an established team at the BAU. The leader of the team is Aaron Hotchner (Thomas Gibson, "Dharma & Greg"), who has been on the show since its inception. Hotchner's ex-wife was killed in season 5, leaving him to juggle his intensive job and care of his young son. The BAU's effective second-in-command is Derek Morgan (Shemar Moore, "The Young and the Restless"), who was at one point offered a position as unit chief of the FBI's New York office. Although he turned down the position, Morgan has filled in for Hotchner as unit chief of the BAU.

Morgan also forms strong bonds with his coworkers, especially Penelope Garcia (Kristen Vangsness, "Pretty the Series"), Dr. Spencer Reid (Matthew Gray Gubler, "(500) Days of Summer," 2009) and the departed Prentiss. Garcia is the BAU's resident computer geek -- an eccentric and flamboyant hacker whose optimism buoys the team even as they investigate the horrors people inflict on each other. She and Morgan have a flirty relationship, and although they aren't a couple, Morgan did tell Garcia he loved her while she was being pursued by a killer with a hero complex.

Dr. Reid is as unrealistic as he is loveable. With an IQ of 187, three PhDs and two bachelor of arts degrees, he joined the BAU at the age of 22. In reality, you must be 23 to be an FBI Special Agent and 26 to obtain Reid's title of supervisory special agent. As a result, he is always introduced as Dr. Reid in an attempt to lend him some credibility as an FBI agent. Reid's mother suffered from schizophrenia, and he exhibits some symptoms of the same illness, as well as having Asperger's syndrome.

Rounding out the team are Jennifer Jareau (A.J. Cook, "Tru Calling"), also known as JJ, and David Rossi (Joe Mantegna, "The Simpsons"). Jareau took a brief break from the BAU during season 6 when she was promoted to the Pentagon before returning the following season. Rossi is a veteran of the BAU, having worked there in the early days before retiring to become an author. He rejoined the BAU in season 3 after another member departed.

"Criminal Minds" spends a great deal of time examining the links between past events and present actions. The criminals tend to have backstories that explain why they do the horrible things they do, and many of the characters on the BAU team suffered childhood trauma as well. Catch a new episode of "Criminal Minds" Wednesday, Nov. 12, on CBS.