Left to cope with their mother’s death, Aaron and his younger sister, Maya, played complex games of hide-and-seek. During one of these games on the roof of their house, Aaron suffered an aggressive outburst of anger. He accidentally pushed Maya off the roof, causing her to fall to her death.
To understand why Aaron was screaming and why his father locked him away, you have to look at the tragic sequence of events that shattered the Peterson family: who was screaming in hello neighbor act 1
Here's a more detailed story based on the game's narrative: Left to cope with their mother’s death, Aaron
While the early alpha builds left this mystery open to wild fan theories, the official series lore established across the main games and the prequel spin-off, Hello Neighbor: Hide and Seek , explicitly confirms Aaron's identity and the tragic backstory behind that scream. The Tragic Lore Behind the Act 1 Basement To understand why Aaron was screaming and why
If you’ve played Hello Neighbor Act 1, you’ve definitely heard it: a distant, terrified scream echoing from inside the Neighbor’s house, usually right after you trigger certain events (like breaking a window or entering the basement stairs for the first time).