Leaving out the firearms-related aspects, why weren’t the kids noting down things like car make and model, color and license plates? A $300 point-and-shoot camera with 40x zoom would have gotten enough detail to nail down the make and model, and perhaps the plates as well.
"...why werent the kids..."
I don't think the teenagers were trained in defensive combat as you apparently were and were overwhelmed by the 9 individuals who stormed the house...........
The first and foremost thing in my mind if I was a teenager was to hide to save my life. I don't think I would be concerned about hanging around the front door or living room window trying to write down the makes of the vehicles and their license plates...........Sheesh!