Laylanee "Cat" Adams, a.k.a. "Miss .45" and "The Black Widow Killer", is a misandris, psychopathic, narcissistic, and international prolific serial killer, hitwoman, and later proxy killer who first appears in Season Eleven of Criminal Minds. She later reappears as the secondary antagonist in Season Twelve as the mastermind in a vendetta against Spencer Reid. She returns again in Season Fifteen for a final confrontation with Reid and the BAU.
Cat is a charismatic and extremely manipulative woman who thrives from psychological seduction and was prone to commonly target men who remind her of her father.
As a child, Cat was abused by her father Daniel, who later went away for manslaughter related to the death of her mother, his wife Laila. She was sent to a foster home, but she was abused by the foster father, whom she eventually killed. In 1987, Daniel was released and left the U.S. shortly afterward. As a result, Cat traveled around the world in search of him, hoping to kill him as punishment for his actions. However, when she couldn't, she channeled her rage towards other men.
Cat eventually became a member of an online network of hitmen (though Garcia would later say that connection was "loose") that cropped up after the dismantlement of the Silk Road by the FBI in 2013, and she became known as "Miss .45.” Having developed psychopathic tendencies, Cat was the only member of the network who preferred to kill her targets up-close and personal, in contrast to the long-distance kills carried out by her colleagues. Though she was faithful to a vast majority of her contract kills, she actually double-crossed three of her clients when they wanted her to kill their wives, as said clients reminded her of Daniel, who she was still searching for.
Kat appears for the first time and meets Reid in disguise at Henry & Gleen's Grill Bar. As the two sit down, Kat asks Reid about his wife and how long he is married that Reid answers for four years. Cat then asks Reid to show him what he does. Soon after, Rossi and JJ appear, undercover, in the restaurant. Cat later realizes that Reid is not married and says that his ring is new and he is lying. She also realizes that Garcia is listening to everything through Reid’s tie, and greets her. She later takes a gun and points it under the table towards Reid. She says she knows that JJ is there, and wants her to leave. She then says what she thinks to be the BAU’s plan to capture her, and for the most part it was correct.
Reid told her that two members of the network, Zac Rubenis and Barry Plyman, are dead. Cat then asked him why he took a break from work, which he deflected. Rossi starts moving towards them, and Cat covers up Reid’s mic and says she will kill him. In turn, Reid tells her everything about his mother and her condition (schizophrenia) and how he left to go help her.
However, Cat does not believe her story and believes that Reid is hiding something. She later says that Reid has a few minutes and that she has taken the other agents in the restaurants, but she does not know that Lewis and Morgan are there. After the stopwatch runs out she asks why would sit her down for thirty minutes. After a short conversation, Cat reveals she has a partner somewhere in the restaurant. Lewis and Morgan manage to figure out who she was (the bomber) while Reid manages to fool Cat by saying that her father is alive. When she exits the restaurant, she sees that she was deceived and goes to prison.
It was revealed that when Cat was arrested at Mount Pleasant Women's Corrrectional Facility, she had to stay in a solitary confinement for six months, which left her unbalanced. A year later Cat somehow got in touch with Lindsey Vaughn and along with a prison guard named Lionel Wilkins, put together a plan to incriminate Reid. They soon discovered about Peter Lewis, and used M.O. to the plan, when Lindsey kidnapped Reid's mother, Diana, the BAU then soon invades the double house that resembles Lindsey and Peter, they soon find an IPad that shows Cat that simply starts insulting and she demands that Reid will visit her in prison, because it was he who arrested her. Soon after Reid and JJ go to the prison to visit Cat, which she then smiled and called him Spencie.
Reid soon demands that Cat tell him where Diana who is Reid's mother is, Cat then interrupts him by saying that he treats her like a criminal, and that they will play the game her way, she then kicks a chair for Reid sitting down, Cat asks him if he liked the prison, and he says no, Cat then asks him why he didn't go crazy, after that Cat asks him to close his eyes as if she were the first woman he seeing after leaving prison that he ends up seeing a fantasy world with Cat, she soon tells if he doesn't want to kill her or hurt her that Reid says no and then Cat says we'll play another game and Cat alone, then Spencer asks if it's going to be the same game to ask the questions and that Spencer may ask what he want and he only has a guess and if he wins Cat wrath tells Lindsey released Reid's mom, and Cat tells Spencer he has 4 hours. After a while, Reid said she knew the secret, and that after she was arrested she studied Reid and manipulated him by incriminating him, treating her as a criminal just to prove that Cat and Reid are the same, after she bored says she understands nothing, Spencer soon tells us that psychopaths got in easily, after that Cat asks him what pain he would invest, she soon mentions mentor and agent Jason Gideon, Reid then says no because he says how about Agent Derek Morgan and his fault for not visiting his son, Spencer then says he was in prison, Cat then asks him that he had time and why he didn't go, Spencer soon tells him that he was distraught trying to help his own mother, and then Spencer says he would have no shame in admitting it and that Morgan would have. Spencer then asks Cat what he didn't admit to, he then talks about love for yours so then he realizes for Cat, then Cat denies that, Cat then says she gave Reid a clue and she soon says she's pregnant leaving Reid shocked with such information, Reid then refuses to believe that his son is because Cat is in jail, Cat tells Reid to asks him how he had the baby, Cat then says he sent Lindsey damn him and that he gave instructions to pretend to be Maeve Donovan. Reid's ancient girlfriend, she then teases him by saying the worlds Maeve said to Spencer. Then Spencer says if his son is his soonerm he tells Cat that he could take her child and that he would lose the interest of child as a child would lose interest in the hambster, and that the child only has a purpose that would be to keep him still in the game, and that Reid says that his mother is dead, but Cat soon denies that she still not dead, Spencer soon leaves and infuriates Cat and she then decides to let him talk to Lindsey.
Cat then calls Lindsey and she says Cat called early, Lindsey then says that if he has come, Cat then says she has to prove her life, that Lindsey soon shows Reid's mother screaming, and Reid picks up the cell from Cat hands Lindsey then shoots the car and drives away, after that Spencer gets enraged with Cat and asks what that Lindsey said he called early, and Reid says it was a signal to kill Spencer's mother, and Cat soon says not knowing, Spencer then demands to know the truth, Cat teases him saying that his mother is an idiot dying Alzheimer's and then she says if she dies it will be his fault. Spencer then asks for control and overturns the table he attacks Cat trying kills her, JJ tries to stop him later and calms down. After Spencer tells him to dance with him so he can say what he means, Cat tells him he wanted to be uncomfortable in the same way it was for Cat herself, so the team soon realizes that Cat has a third accomplice that a guard who works in both Cat's and Reid's jails, they soon find out it's Lionel Wilkins. After Reid tells Cat he was scared, but he soon says he liked to poison the other detainees, and he says he had a thousand ways to escape the situation and was the one that caused the most pain, then Cat says his team is already on the way and also tells Reid that they are going to fall into a trap, after that Cat tries to get Lindsey to kill them all and Spencer soon tells him that it is not his son but Wilkins's, then furious Lindsey surrenders and is arrested by murders. Then in the end Cat really admits defeat by saying that she and Reid deserve each other, and Reid later handcuffs her and walks away.
Shortly before her execution, Cat Adams executed one last plan to ruin Reid's life and to get revenge on him for outsmarting her. Under her instructions, her former cellmate, Juliette Weaver, kidnapped the father and sister of Reid's date, Maxine Brenner. In exchange, she would get revenge on her ex-boyfriend. Her last wish is to go on a date with him. Afterward, she and Reid kissed outside his apartment, in which Maxine sees them. Cat attempts to drive a wedge between Reid and Max by telling Max about Reid's actions towards her, including him being falsely responsible for her miscarriage before asking Max if anyone has hurt her. After Max tells them about her abusive ex, she leaves with Prentiss and they save her father and sister. It is later revealed that Max was working with the team into arresting Juliette and saving her father and sister; in which Max admits she made up the part about her ex being abusive to gain Cat's trust. It is also revealed Reid was not responsible for her miscarriage as she miscarried months after the last visit.
Cat targeted various people through her capacity as a hitwoman, though her favorite target was married fathers who actually hired her to kill their own wives, because they reminded her of her father. Once she had her victims in a highly compromised position, she would kill them by shooting them with a .45-caliber handgun, hence her nickname. She briefly mentioned that she would be so good at manipulating that she could get her targets to kill themselves, though it is unknown if that is indeed the case. During the standoff at Harry & Glenn's Grill and Bar, she held Reid at gunpoint with a .40-caliber Springfield Armory XDM handgun (presumably the same gun she used to kill her victims) and coordinated her actions with Sharon Mayford. Throughout the latter half of Season Twelve, she coordinated her actions with Lindsey Vaughn and Lionel Wilkins.