Sera Morrison

Sera Morrison is a psychopathic teenage killer who appears in "All That Remains".

Background
Sera was a high-school senior with a 4.0 GPA; accepting an early admission to Stanford. She especially excelled in writing, most likely taking after her father, Bruce. She appeared to be a normal girl, but in reality was a psychopath who was viciously jealous of her younger sister Katie and also hated her mother Judy, as she believed she loved Katie more than her. Sometime in 2012, a year prior to the events of "All That Remains", she orchestrated a plan to kill Judy and Katie and pin the entire thing on her father, who was suffering from dissociative identity disorder. Sera eventually murdered Judy during a blackout on February 4 and disposed of the evidence, letting her father take the brunt of suspicion. Over the following year, she orchestrated events for her next murder: she reached out to Jeff Godwin, her mother's suspected lover, claiming that she needed a father figure and confided in him her father's drunken outbursts. She also cut off Bruce's medications, allowing his alternate personality, called "Johnny", to slip through, along with his drunken rages; the latter helped her convince Katie to call an abuse hotline several times. All of these would point to Bruce being the killer, at the same time that would give her several strong alibis.

All That Remains
On the first anniversary of Judy's disappearance, "Johnny" takes the girls to an abandoned building in the forest, located near a river, and leaves them as a way to scare them. Sera murders Katie there, beating her over the head and throwing her in the river. She then takes a shotgun that was at the building and vanishes into the surrounding forest. Investigating, the BAU finally come across her, disheveled and apparently in shock, and take her to the hospital, still thinking she is a victim. JJ comforts her, admitting that she is a mother, in order to help her talk about what had happened. Keeping up her appearance, Sera confides how Judy would wrap her up in a homemade quilt. Instead of talking about what her father had done to her and her sister, she asks to talk with her father, so she is brought to the precinct and into the interrogation room where he is held. After allowing her father to ask for her forgiveness, she starts a confrontation with him, presenting her scars, asking about her mother's whereabouts, and angrily demanding that he confess.

After the outburst, JJ takes Sera home. JJ becomes increasingly suspicious of Sera's unusually calm behavior as the conversation shifted to the cold temperature of the house. Sera goes to take a shower while JJ makes some tea for both, all the while showing not even a single sign of grief about her younger sister; JJ remembers how she was after her sister Rosaline died from committing suicide. In turn, Sera notices that she may have put herself in shaky ground with the profiler when she hears her talking on the phone. She makes her presence known to JJ, who reacts swiftly and mimics a conversation with her own son, when in fact she is relaying her suspicions to Blake, Morgan, and Reid. However, Sera is unconvinced and her discomfort increases. As a result, she returns upstairs and turns on the shower to cover her moves. Sera then goes to retrieve her father's revolver, which she had concealed well enough that the police missed it during their search that same day.

Meanwhile, JJ, thinking she is in the shower, returns to the basement, having remembered something odd about the storage boxes, full of quilts and mementos Judy had collected through the years. Sera, armed with the revolver, follows JJ and watches as the agent discovers the necklace and earrings taken from Judy after her murder. Sera holds JJ at gunpoint from a vantage point on the stairs and admits that she hated Judy and Katie, explaining her view of how Katie had stolen her mother's love from the moment she was born. Bold and secure in her own intelligence, she dismisses JJ's attempts to pull out her own weapon, claiming that she can pretend a form of PTSD had kicked in when she attacked JJ. In the meantime, Morgan and Reid show up to the house and find them. Confronted with this new threat, Sera pretends to be panicked and tries to win them over to her cause. Morgan plays along to get Sera to lower the gun. When she does so, Reid, who had been keeping his gun trained over Sera's head the whole time, arrests her despite her protests.

Profile
No official profile of Sera was made since the investigation was focused on her father. However, JJ deduced that she was a psychopath from her unusually calm attitude and her lack of mourning for her sister. Sera is highly intelligent, manipulative, and ruthless. She was motivated by anger and jealousy towards her sister, Katie, who she believed ruined her life.

Modus Operandi
Sera killed her sister Katie via blunt-force trauma using the grip of her father's revolver, and then disposed of her body in a nearby river. Though it is unknown how Judy died, it can be assumed that Sera applied blunt-force trauma to her as well.

Real-Life Comparison
Elements of Sera's case are similar to the disappearance of Susan Powell.

Known Victims

 * February 4, 2012: Judy Morrison
 * 2013:
 * February 4: Katie Morrison
 * February 6: Jennifer Jareau

Appearances

 * Season Eight
 * "All That Remains"