- "The time of vigilantes is coming to an end. Because how can you idolize someone hiding in the shadows who won't show his face? Who refuses to own up to his shortcomings and culpability? It's not a hero, it's a coward."
- —Samanda Watson to Oliver Queen[src]
Samanda Watson is a special agent of the Federal Bureau of Investigation. She investigated Oliver Queen, the mayor of Star City; regarding if he is the vigilante known as Green Arrow. When Oliver desperately needed help to take down Ricardo Diaz, she offered the FBI's support in exchange for Oliver confessing his secret and being sent to Slabside Maximum Security Prison.
Investigating Oliver Queen
After a photo of Oliver Queen was circulated by Channel-52 News depicting him dressed up as the Green Arrow, Watson arrives in Star City to investigate him for his alleged crimes. During the investigation, she interrogates the other members of Team Arrow, except for Curtis, whom she hadn't been able to reach. It is later revealed that she confronted Rene Ramirez, having discovered his identity as Wild Dog, and blackmailed him into agreeing to testify that Oliver is the Green Arrow. If he refused to testify then she threatened to bring him down and would prevent him from being reunited with his daughter.
During Thanksgiving, Watson arrests Oliver for the crimes that the Green Arrow had committed. Oliver was taken into custody in front of his son, William, and Oliver promised that once he was released he would sue her for malicious prosecution. Watson did not care because she believed that she had all the evidence she needed to lock him up for good. She tried to convince him to sign a confession, but he refused and demanded to see his son. She later attended Oliver's trial, which was postponed temporally. After Oliver announced that the Anti-Vigilante Bill had passed, Watson confronted him and told him that she was returning to Washington, but she would be back for Oliver's trial.
When Oliver's trial was moved up a week earlier, Watson was not present in court for unknown reasons; unfortunately for her, Oliver was acquitted of all charges of being a vigilante.
Aiding Team Arrow
Sometime later, after Oliver was running out of options on how to deal with Ricardo Diaz's hostile take-over of Star City, he was left no choice but to go to her. Watson agreed to help him take down Diaz, but it comes with a price, half of it being admitting he was the Green Arrow, which he did with very little hesitation.
After they agreed on a deal, Watson sent in a number of FBI agents into Star City to assist Team Arrow. They first raided the main police precinct and took out and detained Diaz's men. After a few skirmishes, one that nearly killed Watson and Rene Ramirez in a bomb, Diaz contacted them and demanded Mayor Quentin Lance to order the FBI out of town, or else he would kill Laurel. After Quentin seemingly bretrayed Watson just so that he could be close to Laurel, Oliver told her that Lance had a pacemaker which could be tracked before he left. Felicity hacked into the frequency of the pacemaker and tracked him down to Diaz's safe house. After a fight ensued between the combine forces of Team Arrow and the FBI against Diaz's men, they rescued Quentin and Laurel. They also retrieved intel from Diaz's personal thumb-drive which were detailed files on his entire operation, which included those on his payroll, enough intel to liberate the city from Diaz's grip.
After the mission and Quentin was in the hospital undergoing surgery from a gunshot wound he received from taking a shot for his daughter, Watson came to arrest Oliver for breaking the law and would be sent to super-max prison. However, just before she took Oliver away, Oliver, the rest of his team, Laurel, and a just-arrived Sara Lance received word from Dr. Schwartz that Quentin Lance died. Watson told Oliver that sadly this changes nothing, despite her feeling sorry for his loss and escorted Oliver out. After a last visit from Felicity Smoak and Oliver's son, William, Oliver with Watson held a press conference and Oliver told the world he was The Green Arrow and was going to jail. He told the city that others will carry on the fight for him in his absence. While that was going on, Diaz went into hiding with his new allies while, under Samanda's orders, the FBI arrested all those on Diaz's payroll, thus freeing the city from Diaz's hold over it.
After which Watson took Oliver in and brought him to prison, completing her duties.
Chasing Ricardo Diaz
Five months later, even though she is fully blamed for putting Oliver in prison and started the anti-vigilante law in the first place. after Felicity failed to capture Ricardo Diaz with A.R.G.U.S.'s help, she goes to Agent Watson and demand to fufill her end of the deal she made with Oliver and help her take down Diaz, once and for all.
- "Just because the system is flawed doesn't mean it shouldn't exist. Even someone like Ricardo Diaz needs a lawyer, a fair trial. We protect the rights of people who don't deserve them 'cause it's the only way to protect them for everyone."
- —Samanda Watson[src]
Samanda Watson is similar to Quentin Lance at first; as she is going after Oliver Queen, also known as Green Arrow, because he is a vigilante (disregarding the fact that vigilantes are not in the F.B.I.'s jurisdiction; it is in the jurisdiction of local law enforcements) she is very calm and level-headed, as she did not display any signs of anger when she was interviewing each member of Team Arrow respectively, to gather evidence that Oliver is a vigilante. She is ruthless as she arrested Oliver at a Thanksgiving event for the crimes charged on Green Arrow in front of his son, proving that she doesn't care how she prosecutes her suspects in front of the people close to them.
Watson is very arrogant to the point of having a massive ego, as she believes being an F.B.I. agent makes her superior to Oliver who is the mayor of Star City; legally it doesn't (proving just how deluded she is) when she was in the mayor's office waiting for Oliver (despite the fact that she didn't make an appointment to see him) she arrogantly told him she didn't give a damn, when Oliver could've had her arrested for illegally trespassing in the mayor's office (as she did not have a search warrant or a warrant to question him); her arrogance is also to the point of being delusional, as she believes because she is an F.B.I. agent, that the laws don't apply to her; legally it does.
Watson is quite immoral and dishonorable; when Oliver was away with Slade Wilson, she interrogated Oliver's teammates "thus widening her net" behind his back, a sign that she will use and go after anyone close to him to gather evidence and blackmail anyone to testify against Oliver.
Watson does seem to have a sense of humor, as she took time to taunt Oliver on how he couldn't stop Ricardo Diaz as Green Arrow or the mayor despite knowing fully well the answer and also lightly mocked Rene Ramirez for how bad he was at keeping his vigilantism career a secret.
However, despite this, Watson did displayed some sadness for the death of Quentin Lance, saying that she was sorry for Oliver's loss. She doesn't know it was her fault that Star City crime wave and corruption started when she arrested Oliver and the anti-vigilante act started.
In spite of being a loyal FBI agent and despite all her corrupt methods, Watson still has a sense of honor, as acknowledging that her deal with Oliver was not fulfilled as Diaz was still out, she was willing to go out of her way by disobeying her boss to help Felicity Smoak track down and capture Diaz, even going as far as putting her own life in danger against the Longbow Hunters.
- High-level intellect/Leadership: As a FBI agent, Watson is very intelligent. An expert investigator, she is able to follow every lead to discover the truth behind any crime. Watson was able to figure out that John Diggle is posing as Green Arrow, to divergent suspicion that Oliver Queen is a vigilante, who is under investigation by the FBI (albeit without any evidence); she also somehow discovered that Oliver was previously the vigilante known as the "Hood/Arrow" and that John poses the vigilante archer clearing the latter suspicion of being a vigilante. She also has excellent leadership skills, apparently having a leading role in the F.B.I, as she led the agents sent to help Team Arrow battle and defeat Diaz despite his control of the Quadrant, a highly massive group of criminals.
- Expert combatant/Martial artist: As an FBI agent, Watson is highly trained in combat, allowing her to stand up to a member of the Longbow Hunters, but was no match for her.
- Expert markswoman: As an FBI agent, Watson is well trained and proficient in the use of firearms. She was able to shoot down many of Diaz's men.