While Oliver Queen was unambiguously a hero by the end of Arrow, he was arguably a serial killer early in the show's run. Season 1 saw the vigilante on a quest for revenge, slaughtering various criminals named in his late father's personal journal. While almost all heroes start off with struggles and have to grow into the hero role, Oliver had a particularly long way to go.

In his five years away from the rest of the world (not all of it spent on the island of Lian Yu), Oliver learned the skills that he needed to eventually become the hero Green Arrow. He learned how to fight and survive, but also gained a reason to do so. When his father, Robert Queen, confessed to his wrongs, Oliver was given a mission: to go back home and save Starling City.

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Oliver’s methods of saving Starling City in season 1 of Arrow weren’t exactly heroic, leading to a massive number of deaths in his wake. Given how many people he killed, it might be more accurate to think of Oliver as a serial killer in the first season, rather than a vigilante.

Arrow Oliver Queen

No matter his intentions, Oliver had 55 confirmed kills in the first season, a number comparable to the more prolific serial killers in the real world. True, Oliver had some justification for his crusade, but not enough to warrant such a gross loss of life. He spent the first season preoccupied with his father’s list of those who oppressed the people of Starling City. There were times that he went for the more peaceful route, but Oliver generally defaulted to killing those in his way. He didn't reserve this degree of violence for just those on the list either, as most of the deaths were security guards — ordinary people just doing a job.

While Oliver was ruthless, there were reasons he did so. The Starling City police were incredibly corrupt, so he couldn’t trust the justice system to take care of anyone properly. He had also spent time working for ARGUS, where black ops and ruthless elimination were routine under director Amanda Waller. None of this made it right for Oliver to kill so many people, but it explains why he did.

Thankfully, by the end of the series, Oliver had improved greatly and become a hero. The series finale is built around this, contrasting Oliver’s actions in Crisis on Infinite Earths with the ruthless killing machine he was back in the first season. Ultimately, Oliver's death is the conclusion of a series-long redemption arc. His great sacrifice during the crossover event saved countless lives, and more than makes up for his actions in the early days of Arrow.

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