Decades of historical evidence to the contrary.
If you’d like to have an informed opinion, at least engage with the academic material. Otherwise you come off sounding naïve, insisting that complex problems have simple solutions.
Edit: maybe my ears are a bit sensitive, but I can’t help but hear a faint whistle in the wind, maybe only at a frequency a dog could hear. But no, surely not here in gentlemanly company.
I mean, trivially, using our brains for a nanosecond, what if that 1% of the population is almost always 16-18 year olds when they commit those violent crimes. The 16-18 demographic is roughly 4% of the US population (Google). That would mean locking up 1 in 4 high school students for 6-20 of their most formative years, and thrusting them back into society with a “Mission Accomplished” banner hanging behind you.
Play with the numbers a bit (maybe it’s 1 in 20), but the point stands. Using imprisonment to try to quarantine a demographic that is perceived as irreparably violent is a barbaric, sophomoric idea that has very little evidence of success in the modern era.
The reason I brought up youth is because, unsurprisingly, most violent crime is performed by people who don’t have a fully-formed prefrontal cortex. Feelings of invincibility and a sense of not having much to lose.