The theory centers on Joyce Byers, the mother of Will Byers, the first son kidnapped by the monster that feeds on Hawkins. It is her tenacious efforts that unearth much of the mystery surrounding the city of Stranger Things.
Fans have come up with the idea that Joyce may actually be a murderer with a child’s blood on her hands. In Season 2 of Stranger Things a little boy in a cowboy costume is seen wielding a fake gun.
Fans point out that both the boy’s hat and bucket reappear in Stranger Things Season 3, Episode 1 at Joyce’s store giving the theory that he was able to kill the boy.
Fans of Stranger Things have also posited that Joyce could be displaying the boy’s possessions in plain sight, which would somehow allow her to avoid suspicion.
However, the same fans who created the theory admit that there is little to no evidence to support it. The only proof given comes from Joyce’s slightly odd characterization in Stranger Things.
In a show with so many inexplicable oddities, there is no shortage of Stranger Things fan theories, but based on the evidence, it is highly unlikely that Joyce Byers is a secret serial killer who somehow managed to carry out the murder.