I listed the reasons school shooting take place earlier. Strict teachers is never included in these but bullying, abuse, neglect are, mostly at home, but also through media. It's already listed that he was bullied at school. The teachers possibly not doing anything about it could have lead to him shooting a few of them, along with his grandparents, who could also have contributed to the abuse, although it's said they were close, so it could just be the bullying he received at school. . Many combinations that can happen in these matters, but strict teachers highly unlikely. He also has a history of researching school shootings, so that anger was coming from a while back. No, strict teachers do not cause school shootings, as targeted school violence is a highly complex phenomenon driven by interconnected psychological, social, and systemic factors rather than the actions of a single educator