I have not been to a school in many years, so I cannot speak of any changes in school stature or the such. The observation that children are becoming smaller is an optical illusion because you, yourself, are growing.
There was an incident a month ago where a young teen-year-old and his friend shot a female teen of roughly the same age on a busy intersection. Supposedly they were all friends and the reason for the subsequent murder was unknown. On a whim, I'm guessing.
Another incident, more recent, was of a child around the age of fourteen that shot his soon-to-be stepfather to death. He brought the gun to school and told his friends all about what he was planning to do. He even told his best friend to hide the gun in their locker in case someone 'told' and they did a search. No one had the common sense to bring it up to an adult or tell anyone. Later that day he shot and killed his stepfather in the head. His excuse was that this person was beating him and his mother, and that he had to protect his mother. But the mother had no freaking clue about this. The kid is being tried as an adult and seems surprised that he is in trouble and going to jail over this.
There have been repeated threats of school shootings or bombings in the area. None of it happened. On the news a few years ago a kid was shot by a gang outside of his school, in the parking lot. That set the news ablaze in a frenzy of melodrama and media panic. Now I hear that metal detectors are all the rage to prevent such things.
edit - edited in information on the stepfather shooting.