"Riverdale" chapter 4 four titled "The Last Picture Show" will hopefully shed light on Jason Blossom's death. Cheryl's twin brother was the school's golden boy, and his tragic death is still a mystery. So who killed Jason?

Chapter 3 titled "Body Double" featured a backstory of Jason, opening up possible motives for his murder, ComicBook said. Many people believe that the Cooper family has something to do with Jason's death. The reason? The show has hinted that Betty really has some deeper mental health issues.

Last week's "Riverdale" episode featured Betty taking on the persona of her sister Polly while trying to exact revenge on Chuck Clayton after the latter slut-shamed the girls of Riverdale High. Betty screamed Jason's name - the same person who could be the cause of Polly being institutionalized. Does this mean that Betty has a secret dark side? Even Veronica was shocked, and when she asked Betty what she was thinking, Betty answered she can't remember anything, Polygon said.

Lili Reinhart said that her character has a seemingly perfect facade, but on the inside, she is very broken and is slowly trying to piece herself back together. "She struggles with mental health issues, and anxiety and self-harm," Reinhart said. When Betty told Veronica that she does not remember anything, this could mean that there may be terrible things that she has done but can't remember - at least this is how some fans speculate it.

But Betty has an alibi. She said that during Jason's death, she was at her internship in Los Angeles. If Betty is telling the truth, a killer is still clearly on the loose, and anyone in Riverdale could be a suspect. Many fans are hoping that Betty is not the killer, but the fact that she has mental issues may be a serious focus on coming episodes of "Riverdale."