Joker is not a film for kids. It comes with an R-rating and fully indulges in its pass to include violence, foul language, and other strong material. Throughout the course of the movie, the main character commits all manner of hideous acts, from cold-blooded murder to breaking and entering and stealing.
The following list will reveal the worst things he does throughout the film. Most stories try to portray their villains with at least an ounce of sympathy, and while people treat Arthur Fleck (Joaquin Phoenix) despicably throughout the run time, none of the things he does are justified, truly earning him his villainous status.
Steals His Mom's Medical Files
While investigating whether or not Thomas Wayne's claims about his mother's mental health are true, he goes to the Arkham State Hospital to find her records. When the clerk refuses to give him the file without proper documentation, he quickly grabs the folder and struggles with the employee until the papers are firmly in his hands.
We're unsure of the prison sentence one would receive for stealing official state records, but it's nothing compared to the sentence he would get for his other crimes. It was a relatively harmless act, but it kick starts more serious transgressions.
Stalks Sophie
Sophie is Arthur's next door neighbor and he clearly harbors some affection for her. Given his troubles, he chooses to express this by stalking her to her daughter's school and place of work. He makes no attempt to contact her, but she notices and confronts him at her apartment... or at least that's what the audience is led to believe at this point in the movie.
Her reaction to his confession is light and she plays it off as a joke, which in hindsight was the first sign that things aren't as they seem.
Kills His Mother
After discovering his Mother's past incarceration and the lies she fed to him throughout his life, Arthur pays her one final visit while she is in the hospital. After a short monologue, he takes a pillow and smothers her until she passes.
In real life, a pillow is said to be a terrible tool for such a task, as air could easily make its way to the potential victim, but it serves its purpose in the movies. It's probably a lot easier to do when the unfortunate soul is in a weakened state, like Arthur's mother.
Broke Into Sophie's Apartment
After doing away with his adopted mother, he breaks into his crush's apartment. When she walks into the living to find him sitting on her couch, Sophie is frozen with fright. It's here when audiences learn that their prior encounters were just Arthur's fantasies. She begs him to leave and the next shot shows him leaving the apartment as ominous music plays.
Sophie never shows up in the movie again, and while we see no blood on him as he walks, Arthur is disturbed enough at this point to make the audience believe he could have done her serious harm.
Reads His Mother's Letter
Penny insists that Thomas Wayne will help them when he gets her letters. Finally, Arthur decides to breach his mom's privacy and read the letter, which says the two had an affair which resulted in Arthur. This sends him into a rage, and Penny admits what is written is true.
While it ultimately turns out to be a lie, Arthur takes it as fact as he never had a reason not to trust his mother. Sadly, later events reveal the opposite. She rarely ever told him the truth.
Probably Kills The Psychiatrist At The End
The last shot of the movie sees Joker slowly walking down Arkham's hallways while he leaves a trail of bloody footprints. This comes immediately after a conversation between him and a doctor. One can easily put two and two together to infer that he attacked, and possibly killed, the unlucky medical professional.
He turns one way and quickly runs to the other side of the frame as several orderlies chase him down, then the credits start rolling. It's a chilling conclusion to an already unsettling story.
Stalking The Waynes
After believing his mom's delusions, Arthur goes to Wayne Manor for a face to face meeting with Bruce Wayne, who he thinks is his biological brother.
He tries to entertain the young boy with some magic tricks, but Alfred Pennyworth steps in and gets Arthur to leave. Later on, he sneaks into a showing of Charlie Chaplin's Modern Times to meet face to face with Thomas Wayne, who socks him in the face.
Kills The Three Wayne Employees
The first people Arthur kills are in an act of self-defense. They beat him down in a subway car after already harassing a lone female rider and he takes out a gun and mows them down. Most would argue that he went far and beyond simply defending himself, but he definitely wasn't the one to draw first blood.
It's this moment that sparks the building movement throughout the film that culminates in the widespread rioting during the climax.
Incites Riots
True to the character's spirit, Arthur has no concern for people's safety by the end of the movie. Earlier on he shows mercy to people who treated him well, but during his time on Murray Franklin's show, he seems content to know that he inspired people to violence and is unfazed upon hearing they've led to more deaths.
He doesn't just want to watch the world burn, but he's inching ever closer towards burning it himself. If this incarnation ever returns, one can be sure that making Gotham suffer will be at the top of his priority list.
Kills Murray Franklin
Because the late night television host made Arthur the object of mockery, he makes it a point to personally murder him on stage in front of his audience. He does it abruptly and just like that, Murray is out of the picture.
The act represents a greater statement however, as Robert De Niro played two similar characters in Travis Bickle from Taxi Driver and Rupert Pupkin from King of Comedy. It's as if the film is saying that Arthur is far more unhinged and sinister than these two iconic anti-heroes combined.