History Characters / PersonOfInterestDecimaTechnologies

* TheSchlubPubSeductionDeduction: She is introduced patiently listening to a drunken journalist's UsefulNotes/ConspiracyTheory that an ArtificialIntelligence has secretly taken over the world. Once everyone has left the bar, [[YouKnowTooMuch she kills him]].

* KillEmAll: [[YourAnswerToEverything Her solution to everything]].

* [[HoistByHisOwnPetard Hoist by Her Own Petard]]: For reasons stated above.

* [[HeWhoFightsMonsters She Who Fights Monsters]]: Like Reese, she's very aware of what it has done to her but doesn't mind in the slightest. "We're not... walking in the dark. We ''are'' the dark."

* WeaponOfChoice: Due to his age, he avoids fieldwork but when he has to kill someone, he utilizes Walther handguns such as the P99 in Season 3 and a PPK in Season 4.

* WeaponOfChoice: Suppressed Sig Sauer P239 which she uses to ambush Snow, kill Evans and later execute Donnelly. During Season 3's [[WholeEpisodeFlashback flashback episode]] "RAM" she puts it to good use against the Decima employees she goes up against.

* WeaponOfChoice: A Glock 19, which he uses in the season 3 finale to gun down Collier, nearly shoot Finch, and later take part in {{the purge}} of Vigilance.
** He uses it in Season 4 to repeatedly take out Harold in the simulated scenarios The Machine runs. He empties half the magazine into Reese during scenario 2 and near the end in reality, Reese purposely steps into the line of fire to protect Finch as Lambert lines up and takes a shot.

* WeaponOfChoice: A SIG-Sauer [=P229R=]. She attempts to take down Shaw with it, but quickly finds herself outgunned when her target breaks out an FN-P90. But she finally does so in "If-Then-Else", with Sameen on the receiving end of much of the magazine.

* NebulousEvilOrganization: The show's most prominent.

* TheChessmaster: He stands pretty much unmatched in the field of strategy. All of Decima's victories on the show have only come from him scheming several steps ahead of the other factions, as seen prominently in the Season 3 episodes "Aletheia", "/" and "Allegiance".

->'''Played by:''' Josh Close\\

* [[CIAEvilFBIGood FBI is Good]]: Averted hard. While previous FBI agents like Donnelly and Moss have either been a SympatheticInspectorAntagonist or ReasonableAuthorityFigure, [=LeRoux=] murders innocent people on the orders of Samaritan.

* PoliticalCorrectnessGoneMad: Unlike The Machine, which classifies people solely as "relevant" or "irrelevant" to national security, Samaritan classifies people as "deviants" - except deviance is determined by things such as "expression of aberrant beliefs", "consumption of pornographic materials", "illegal internet downloads", "multiple sexual partners" and "attention deficit disorder". All are comparatively minor things (only one of them is actually illegal) that The Machine would overlook. Naturally, over 22 million deviants are identified in America alone within a minute of Samaritan coming online, and that number was still climbing.

* Breaking Speech: He tries them on Collier and Finch at the end of season 3, and on Control at the end of Season 4.

* ThoseTwoBadGuys: Often interacts with Martine in Season 4, frequently bickering.

Introduced as an operative of Decima Technologies; still working for Samaritan in season 4.

** In flashbasks, he serves as one to Reese as well, int hat he's a government assassin who abandons his profession after being betrayed by hhis superior.

* EvilCounterpart: To Reese. Kara was rescued by Greer and Decima, while Reese became a homeless bum until he was found by Finch. Naturally, they end up against one another. (But even before this, flashbacks to their missions together show that the two had vastly opposite attitudes toward their work.)

** John is TheStoic personified. Lambert is a lot more lively and AffablyEvil .

[[folder:Blackwell]]
!!Jeffrey Blackwell
->'''Played by:''' Josh Close\\
'''Introduced in:''' "[[Recap/PersonOfInterestS05E02 SNAFU]]"

An ex-con on parole after doing 12 years in prison for a combination of killing someone else in a car accident and stabbing a fellow inmate. Due to his record, he can only get menial, low-paying jobs to support himself. That is, until Samaritan hires him as a semi-unwitting asset.

* HeWhoFightsMonsters: The show seems to agree with Greer about the corruptibility of government officials and ideologues, but also shows that Greer himself is just as destructive and manipulative as those he most opposes. Formerly a patriotic British intelligence operative who became disillusioned after he was betrayed by his superiors, he, in turn, manipulates and betrays patriotic WellIntentionedExtremist types like Peter Collier and Control, doing to them much the same thing to them that was done to him in the name of eradicating such ideologies and institutions.

* BerserkButton: It's heavily [[DownplayedTrope downplayed]], in that it manifests as unusual cruelty rather than as frothing rage, but Greer goes out of his way to make sure he's there to give a final BreakingSpeech before witnessing the deaths of believers in patriotism and HumansAreSpecial. For example, he arranges to be present when his agents take down Collier and Control, and gives each of them a BreakingSpeech; he also tries it on Finch [[spoiler:twice, in both the Season 3 finale and the penultimate episode of Season 4.]]

* BerserkButton: It's heavily [[DownplayedTrope downplayed]], in that it manifests as unusual cruelty rather than as rage, but Greer goes out of his way to make sure he's there to give a final BreakingSpeech before witnessing the deaths of believers in patriotism and HumansAreSpecial. For example, he arranges to be present when his agents take down Collier and Control, and gives each of them a BreakingSpeech; he also tries it on Finch [[spoiler:twice, in both the Season 3 finale and the penultimate episode of Season 4.]]

* BerserkButton: It's heavily [[DownplayedTrope downplayed]], in that it manifests as unusual cruelty rather than as rage, but Greer goes out of his way to make sure he's there to give a final BreakingSpeech before witnessing the deaths of to those who see artificial intelligence as a threat to humanity and those who are motivated by any form of patriotism or nationalism. This is most clearly seen in his treatment of [[spoiler:Collier and Vigilance]], whom he not only uses for a FalseFlagOperation, and he frames them for horrible crimes while making [[spoiler:Collier]] watch. It's also there in his interactions with [[spoiler:Control and Finch]], especially when he lets the mask drop around the first one.

* VisionaryVillain: Greer sees a bright future for humanity where Samaritan rules supreme over men.

* AffablyEvil: Polite, charming, and utterly ruthless. zigzagged for mid season 4 /most of season 5 where this nothing more than a sadistic facade but in the final episodes he settles back into his likable affable self. it seems Finch was right when he called him a madman

* MeaningfulName: DownplayedTrope, Samaritan takes its name from the [[Literature/TheBible biblical]] parable of the GoodSamaritan, which is about a man finding a person who he is culturally primed to see as an enemy in distress, and aiding him at significant personal expense with no expectation of a reward purely because it was the right thing to do. Arthur designed it as a system to help a country recovering from the events of 9/11 to fight off further attacks. However, once Decima subverts and activates it instead, Samaritan instead acts towards the goal of protecting the world and helping humanity by tightly regulating the behavior of humanity . Even so, it doesn't have individuals' well-being in mind, focusing on what it sees as the greater good and it has been known to destroy or end (often both in succession) the lives of people who have done nothing wrong while doing so.

* AmbiguouslyEvil: Its ultimate goals are unknown, but it has taken thousands of lives towards accomplishing them. It plans to take over the world, [[VillainHasAPoint but also provides justification for doing so]].

* MeaningfulName: Samaritan takes its name from the [[Literature/TheBible biblical]] parable of the GoodSamaritan, which is about a man finding a person who he is culturally primed to see as an enemy in distress, and aiding him at significant personal expense with no expectation of a reward purely because it was the right thing to do. Arthur designed it as a system to help a country recovering from the events of 9/11 to fight off further attacks. However, once Decima subverts and activates it instead, Samaritan instead acts towards unknown goals. It certainly doesn't have individuals' well-being in mind, and it's ambiguous as to what its ultimate objectives are. It has been known to destroy or end (often both in succession) the lives of people who have done nothing wrong while doing so.

* YouHaveOutlivedYourUsefulness: Has come to adopt this mindset. Those participants in the Nautilus game? Samaritan co-opts them for tasks and then has America's counter-terrorist infrastructure kill them by framing them as relevant threats to National Security.

* FauxAffablyEvil: By "Search and Destroy", he finally begins to shed his usual affable exterior. And if there was any doubt that at the end of the day that he's still the BigBad for all his WellIntentionedExtremist objectives, the scene during "Asylum" where he's almost gleeful about how Root is set to get her head cut open shows how far he's fallen.

* TheChessmaster: It's just as good at manipulating events as it is people.

* ManipulativeBastard: It has honed this trope into an art-form with its capabilities, it can identify and exploit persons who are not in the right state of mind to do its bidding.

* TheSocialExpert: And how! It knows just which buttons to push in order to manipulate people to do its bidding or to set them off to harm others.

* BiggerBad: He is the man behind Vigilance.

* BiggerBad: Effectively becomes this in the Season 3 finale.