Criminal Minds is quite a popular show among lovers of crime and investigation. The show follows the FBI’s Behavioral Analysis Unit (BAU) as they profile and find serial killers, while simultaneously allowing viewers to get to know the members of the unit and understand their familial bond with each other.

One of the largest parts of Criminal Minds is its main cast. This stands true for any show, of course, but things are a little different with a show like Criminal Minds that ran for 15 years. As one would expect, it had many cast changes, as members left to start their own projects, spend time with their families, or simply take a break from the show. In fact, only one cast member from the first season remained for all fifteen seasons. However, despite the constantly changing cast, show writers seemed to keep to one template for their characters and the actors who played them. As a disclaimer, I have only reached season 10 so far, so my observations may go disproved as I continue with the show, but so far, they have remained true.

Of the seven members of the main cast, only four have remained the same: Dr. Spencer Reid, Aaron Hotchner, Derek Morgan, and Penelope Garcia. The other three have varied over ten years, but each role has been filled by a distinct type of character.

The first is the older, wiser Supervisory Special Agent (SSA) who has almost a paternal relationship with the younger members of the team, and a rocky romantic history. This role was first filled by Jason Gideon, who eventually left the team after his girlfriend was abruptly killed by a serial killer. He was quickly replaced by his best friend David Rossi, characterized by his many ex-wives, penchant for cooking, and witty remarks.

The second is the blonde woman who breaks any stereotypes following blonde women. This role is mostly kept by Jennifer Jareau, a communications liaison-turned-SSA who is especially close to Dr. Spencer Reid and always surprises killers with her fighting abilities. Whenever she was gone from the show, whether on an international mission, working at the Pentagon, or on maternal leave, she was replaced by an eerily similar young, blonde woman whose appearance would be as quick and as easily explained away as her inevitable leave.

The final of these roles is the brunette woman with above-average intelligence and some type of skills that make her invaluable to the team. The first of these was Elle Greenaway, who was especially useful for her skills in catching sexual predators and killers, as well as her ability to speak Spanish. After she left the team, she was replaced by Emily Prentiss, the longest-remaining in this role. Prentiss was multilingual, was a top INTERPOL agent before she arrived at the BAU, and had a mysterious past. After she left following a long and complicated arc, she was replaced by Alex Blake, a linguist who could match Dr. Reid’s intelligence in some fields and had a similar relationship with him as Prentiss did. She left the team at the end of season 9 for personal reasons, and I have just been introduced to Kate Callahan, Blake’s replacement, who also has brown hair and seems to be building a close relationship with Dr. Reid.

While it makes sense that the writers of Criminal Minds would want to keep the same type of character for their roles, such “doubling” threatens to erase individual characters’ identities, instead equating them to simply the overarching identity that all of the replacements fit.