That's correct. We shouldn't be convicting people unless it's obvious.

Have you ever served on a jury? It's easy to get out of jury duty. The people who really don't want to be there, usually aren't. When I did grand jury, everyone wanted to be there and was very engaged. To me this is like saying people aren't interested in juicy gossip, having an opinion, debating the smallest details, and wielding power - that's not been my experience.

But the bigger problem is that, if the process were really so precarious, then that's exactly why we would want stronger controls. There may be a good argument for a different threshold but it isn't this one.

The odd thing is that the incarceration rate in the US is 542 per 100k, but the murderer rate is probably something like 200-350 per 100k.

5.9 homicides per 100k annually [1]. Assuming the average person who commits homicide commits 1 homicide in their lifetime (known homicide distributions support this) then that is 5.9 new murderers per 100k annually. Distributed over expected lifetime that would be 200-350 murderers per 100k.

So, if the US successfully imprisoned every murderer and only murderers, it would still be ~25th (~Nicaragua) to ~80th (~Russia). Nearly 2x the total incarceration rate of France and 3x the total incarceration rate of Germany if only murderers were incarcerated and we used the low estimate.

If we assume that homicide is relatively rare compared to severe physical violence that most nations consider worthy of incarceration, then just imprisoning all violent offenders in the US would likely require 1,000+ per 100k at the low end, over twice the actual rate in the US.

[1] https://www.cdc.gov/nchs/fastats/homicide.htm