The arrival of Mary Louise on Season 2 of Big Little Lies meant that some details from Perry's life before Celeste were sure to emerge. And emerge they did: it was revealed that Perry had a brother named Raymond who died in some kind of accident when they were children. Naturally, fans assumed that there must have been something nefarious going on. An accident is never just an accident on this show. So who killed Perry's brother on Big Little Lies?
Officially, no one killed him. Based on the information the show has divulged so far, Raymond had an accident that cost him his life and it splintered the Wright family. Mary Louise's husband blamed her for what happened and left, causing her to rely more intensely on Perry as the years went by. The show isn't framing the situation as a murder, but that hasn't stopped viewers from coming up with all kinds of theories. And they all point at the remaining Wrights: Mary Louise, her husband Ray, and Perry.
If Ray felt that Mary Louise was responsible for Raymond's death, then it's possible that she was — though I doubt she would so casually accept culpability if she was guilty of outright murder. And she's not the only suspect.
The most popular perpetrator is Perry. It's not a stretch, either; knowing how violent he became as an adult, it's easy to understand why viewers would pin Raymond's death on him. He put both Celeste and Jane in incredibly dangerous situations. Perhaps his cruel streak emerged early. However, Perry confirmed that he was only five years old when Raymond died. And I would hazard a guess that Raymond was the older of the two, since he seems to be named after their dad, which is typically an honor bestowed upon eldest children. While there have been cases of murderous kids throughout history, I find it slightly difficult to believe that a five-year-old did the deed and never got caught. But who knows? It might not have been premeditated. Maybe Perry pushed Raymond and he hit his head. Anything could happen.
But Reddit user rainydaybatsy had a different idea. They thought Ray Sr. might have killed his son. The show has spent a lot of time focusing on how parents affect their children, particularly when it comes to Celeste's twins responding to their father's violence. Even Madeline has been dealing with the ramifications of her father's infidelity, which happened when she was just a child. Rainydaybatsy interpreted those instances as clues about Perry's childhood. They believed that Ray was abusive to Mary Louise and the boys, which may have caused Raymond's death. Mary Louise hoped Perry would grow up to be different from his father, so she can't deal with the fact that he was exactly the same. Perhaps Ray even blamed Mary Louise to gaslight her, which can be common in abusive relationships.
But that's just one theory, and not one that has much concrete evidence. Perry's brother might not have been killed at all; he could have actually died in an accident. Until Big Little Lies provides more details, all fans can do is speculate.