What is an unsub in Criminal Minds? Details explored

In Criminal Minds Season 1, Episode 1, titled Extreme Aggressor, the FBI's Behavioral Analysis Unit (BAU) is called to Seattle to investigate a serious kidnapping and murder of young women. They suspect a serial killer whose identity is not known. While briefing the team, Supervisory Special Agent Jason Gideon refers to the suspect with criminal charges as "unsub."

The team later builds the criminal profile and states that the "unsub" is in his 30s, a white male, intelligent, and probably has a job that involves traveling. Later, as the investigation progresses, the unsub turns out to be Richard Slessman. What does the term unsub represent here or in Criminal Minds? Let's explore this in detail.

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Here is what an unsub in Criminal Minds

Criminal Minds portrays the BAU profiling and investigating serial crimes. The BAU frequently uses the term "unsub" while communicating with each other, referring to some criminals in general. Unsub refers to criminals whose crimes are being investigated but whose identities have not been revealed. The BAU uses psychological insights and behavioral analysis to track down these "unsubs."

While profiling, they filter out the pool of suspects by jotting down the features of the unsubs in the case. However, unsub is different than suspects. Suspects are not proven guilty of their crimes while unsub are unidentified criminals. The suspect's identity is known, but the unsub's identity cannot be determined so far in the investigation.

BAU usually compares suspects with unidentified people with criminal charges and tries to connect the dots, if any. It is a bad practice for the investigator to use any other name for these unidentified criminals than a general word like "unsub."

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Therefore, "Unsub" is short for Unknown Subject, a real FBI term used in criminal investigations. While popularized by Criminal Minds, the term has been in use within law enforcement agencies, particularly in profiling and investigative work. This shows that Criminal Minds portrays the authenticity of the real world backed by strong research.

There could be different types of unsubs, such as serial killers or kidnappers, abductors, terrorists, or mass murderers, among others. Other than features and behavioral patterns, the BAU also investigates the locations where the unsub can strike next.

Criminal Minds aired from 2005 to 2022 and portrayed some suspenseful cases. The show was revived in 2022 as Criminal Minds: Evolution, which continues the story of the original series. The show has been renewed for a 19th Season ahead of the premiere of Season 18. The new episodes are set to drop on May 8, 2025, on Paramount+.