This article is 5 years old; but, sadly, still very relevant.
https://www.theguardian.com/commentisfree/2013/feb/20/no-armed-guards-in-schools
Now, if there was a guarantee that every armed guard would be like the one in CatBus’s story, I don’t think I’d have a problem with it. But a lot of the time, the armed guard doesn’t take the role of a chill beat cop, they become the person in charge of disciplining the students.
Also, I don’t think I’d feel very safe around an armed guard, I’d probably feel less safe then I would without a guard. People with guns make me nervous, not because I’m afraid of guns, but because I can never know if they’re going to use them or what they’re going to use them for.