List of Person of Interest characters


This is a list of characters in the American science fiction crime drama television series Person of Interest.

Main characters

John Reese

John Reese is the name adopted by the former U.S. Army Special Forces soldier and Central Intelligence Agency officer who serves as Finch's armed enforcer to stop future crimes. Presumed dead following a failed CIA operation in China, Reese's real name is unknown. He was nicknamed "The Man in the Suit" by law enforcement, who knows him only in terms of the description given by witnesses.

Harold Finch

Harold Finch is a reclusive billionaire software engineer who built a machine that predicts future crimes and outputs either the victim's or perpetrator's Social Security number. He is known by a series of bird-themed aliases such as Harold Wren, Harold Crow, and Harold Swift. Finch is very secretive and highly conscious of digital security and has successfully erased his own digital footprint. A frequent companion of Finch is a dog named Bear. Bear is a Belgian Malinois with military training who Reese rescues from Aryan Nationalists, who were using him as an attack dog.

Sameen Shaw

  • Portrayed by Sarah Shahi
  • Episodes: "Relevance" – "return 0"
Sameen Shaw is a former U.S. Marine, physician and a US Army ISA operative, first seen as an assassin working for "The Program", the section of the Government dealing with the "relevant" numbers found by The Machine. Her ISA partner Cole begins to have doubts after one of their targets proves to be an engineer working for the government; the assassination is part of the cover-up that conceals the existence of The Machine. As a result, her employers targeted her and her partner and plan a trap to assassinate them. Shaw and Cole's numbers were given to Reese and Finch. That night, Cole is killed. Reese and Finch continue to try to help her and although she initially declines a couple of times, she ends up subsequently working with them on a regular basis. She likes dogs and buys Bear an expensive collar and other presents.
Shaw witnessed her father's death in an automobile accident at a young age but did not exhibit typical emotional reactions to it. In her first appearance, she claims that she has an Axis II Personality disorder and alexithymia, making her unable to feel and/or express common human emotions such as fear or sadness. Shaw attended Med School and once trained as a surgeon; although very technically capable, she was criticized by her superiors for her indifference and lack of sensitivity to her patients and it is implied that she was removed from the program before she could complete her surgical training because of the lack of these emotional characteristics. She is capable of deducing emotionally correct actions, such as rescuing Fusco's son rather than Fusco and taking on Genrika as her unofficial ward. She unexpectedly reveals a hint of emotion by passionately kissing Root before sacrificing herself to save the team.
She is later revealed to be alive and is used by Samaritan to bait a trap for the team. Greer then has Shaw subjected to over 7,000 simulations in an attempt to turn her on the team but Shaw is able to escape, killing Jeremy Lambert in the process. Shaw returns to New York a week later, but because of the number of simulations she went through, has a hard time distinguishing reality from simulation. Root is able to get her to rejoin the team, however, which now includes a fully knowledgeable Fusco. Following Finch's cover being blown, Shaw works with Root to protect him but is separated by a gunfight. She is later devastated in her own way to learn of Root's death. Following Root's death, the Machine reassigns Root's rotating identities to Shaw and she works with Reese and Fusco to stop a presidential assassination by domestic terrorists. She then infiltrates Fort Meade with Reese to back up Finch in deploying the ICE-9 virus into Samaritan.
As the world falls apart from the ICE-9 virus, Shaw visits Root's grave in an attempt to say goodbye, but is unable to. She is then contacted by the Machine who uses Root's voice and She aids her in escaping a Samaritan ambush. During the final battle with Samaritan, Shaw works with Fusco to defend the Machine, capturing Samaritan agent Jeffrey Blackwell in the process. Shaw realizes Blackwell is Root's killer and shows her cold rage but she first decides to listen to the Machine. Before Shaw and Fusco leave the Machine per Her request, the Machine passes on a final message from Root to Shaw, who is able to finally say goodbye to Root. A few moments later Blackwell escapes after seriously wounding Fusco.
A week later, Shaw hunts down and kills Blackwell in revenge for Root. She then meets a recovering Fusco in a café, neither of them knowing if Reese or Finch survived. Shaw then takes Bear and walks down the street before being contacted by the Machine's copy, still using Root's voice, and smiles at a nearby camera. It appears that Shaw, chosen again as the Machine's Primary Asset and now also somewhat of an Analog Interface, will continue working numbers with the Machine.

Root

  • Portrayed by Amy Acker
  • Episodes: "Bad Code", "Firewall – "return 0"
Root, born Samantha "Sam" Groves, is a highly intelligent computer hacker and contract killer, obsessed with Finch and the Machine. Aside from her extraordinary intelligence, she has also displayed an uncanny ability in the use of firearms, a very high threshold for pain and a proficiency for social engineering. She has successfully posed as a high-end psychiatrist, an assistant to the United States Special Counsel and as a legitimate FBI agent.
She was raised in Bishop, Texas, where she lived until her mother's death. According to Sam, in discussions with Finch, her mother told her to "follow her talents" — and she was good at inflicting harm on others without guilt or remorse. As a child, computers made more sense to Sam than people, who she sees as "bad code", admitting she has been waiting her whole life for someone who shared her understanding of technology.
In 1991, Sam and her friend, Hanna Frey, were playing computer games in the local library until it closed for the day. After her friend left, Sam stayed a little longer successfully finishing The Oregon Trail. When she was ready to leave the library, she saw Hanna getting into a car that belonged to Trent Russell, a local man who was a member of the book club. She recognized his car and told the librarian, Barbara,, who later married Trent Russell, what she had seen. However, as Barbara was in love with Trent, she kept the information to herself to protect him, calling Sam a liar and an attention-seeker. This response further damaged Sam's faith in humanity. Two years after Hanna disappeared, Sam hacked into the bank account of a drug lord, and stole $100,000, using the money to frame Trent for the robbery, setting him up to be killed, as revenge for killing Hanna. Sam later moved out of Texas and became a professional assassin and ruthless hacker-for-hire under the alias "Root". Although she doesn't necessarily enjoy it, she has no qualms about torturing or murdering people to get whatever she wants.
She was hired by Pete Matheson to assassinate Congressman Michael Delancey. Through the use of a patsy, Scott Powell, Root was successful. However, her plan to kill Powell afterwards was foiled by John Reese. Ultimately, the operation fell apart as Reese took out one of her men and stole his phone while Finch provided a phone recording to the FBI proving Matheson's involvement. Realizing this, Root killed her client and staged it as a suicide out of guilt for his actions, exonerating Powell. Root cleared out of her location, the dorm room of an uninvolved college student away on winter break, before the FBI, acting on an "anonymous" tip could apprehend her. She had a brief instant message conversation with Finch, acknowledging him as a worthy opponent and said she was looking forward to the next time. She ended the conversation with "Harold", letting him know that she knew who he was.
As part of Root's plan to come face to face with Finch, Root anonymously contacted HR and put a hit on herself, using the pseudonym "Dr. Caroline Turing". Turing's Social Security number appeared through the Machine, making her a person of interest. Reese, discovering Turing was a psychologist, became one of her patients. Later that night, Turing was attacked by four assassins hired by Simmons. Reese managed to get her to safety in a hotel for the night, and the two were unknowingly caught on the FBI's radar. Under Donnelly's supervision, the FBI staged a full-scale assault on the hotel, while HR was trying to get to Turing. With the help of Joss Carter and Finch, Turing was led to a tunnel system under the hotel. Reese instructed her to find Finch at the end of the tunnel, while he was holding off the HR hit men. As Finch was confronted by Alicia Corwin regarding his involvement with the Machine, Root shot Corwin dead. Introducing herself as Root, she tells Harold they have a lot to talk about. Finch drove away at gunpoint, with Corwin's body left behind.
Planning to escape with Finch to Texas, Root stopped in Maryland where she gained access to Denton Weeks' house. She lured him there to overpower and question him about the whereabouts of the Machine. After he told her what she wanted to know, she shot him dead. She did not know that Reese had already tracked her down through her friend Hanna's case. While holding him captive, Root explained to Finch that she does not want to control the Machine but to "set it free" to usher in a posthuman future. At the train station, Reese managed to save Finch and Root escaped. She called him on his mobile phone later that day to thank him for solving Hanna's case and told him that she would be in touch.
Several months later, Root, to gain information, began working, as "Miss May", an assistant to the Special Counsel at the Office of Special Counsel. She continues to find information on the Machine's location and learns about the virus and "reset". She beats Decima to it and receives admin access of the Machine for 24 hours. However, by the time Root, Finch, Reese, and Shaw get to the place where the Machine was stored, She had already moved herself to unknown locations. Root, losing her purpose, is devastated and sent to a Stoneridge Hospital by Finch. While being kept there, the Machine contacts her and Root becomes chosen as the Machine's "Analog Interface". And after going through Machine's reformation project, she starts to work for the Machine and often times collaborates with Reese, Shaw, and Finch. She learns and changes her "bad code" ideology throughout S3 and in Root Path. Throughout S3, she begins to fall in love with Shaw, who unknowingly becomes a part of the reason for Root's reformation. By the end of S3, she is technically full member of the team.
In Season 4, Root continues to work on little projects with the Machine, preparing for the big war with Samaritan. She continues to make attempts to convince Finch to be more of an active player against Samaritan. In "If-Then-Else," she loses Shaw who sacrifices herself to save her and the team. Root then goes on a warpath in search of Shaw for the rest of S4, partially going back to the version of herself before reformation. When the Machine tells Root to "stop" searching for Sameen, she shows disappointment and sadness, leaving the team with a goodbye. She comes back a couple months later and again helps the Machine preparing for the war. She learns that Shaw is still alive and is being kept somewhere in Samaritan's hands. She infiltrates Samaritan's base knowing it's a trap and as a result she is captured. The Machine releases her and Finch by making a deal with Samaritan: giving up the location of Herself. Root then works with Finch and Reese to protect the Machine from being killed by Samaritan and successfully migrates a copy of the Machine in a laptop and custom made suitcase Root prepared in advance.
Once the Machine is successfully decompressed, she and Finch work on debugging the Machine for 2 months. Once it's up and running an open system, the first thing she does is to search for Shaw but is disappointed to find that there were 0 search results. She and Finch get a copy of Samaritan's code and create a mini-clone of Samaritan to run simulations of the war. In "QSO", she finally is able to get the Machine's help to send a message to Shaw via a secret communication channel that is connected to all Samaritan facilities. Root's message, "4AF", stops Shaw from attempting to kill herself and leads her to re-plan an escape. Root finally reunites with Shaw after 11 months of separation in "Sotto Voce". However, in just a week after reunion, Root dies trying to protect Finch from being assassinated. The Machine then chooses Root's voice to talk to Finch and Shaw. The Machine later shows that She not only chose Root's voice but also as Her avatar/proxy in "Return 0". Root was chosen, again by the Machine and continues to "live as long as the Machine lives."