the most serious of crimes where there is no doubt of guilt
this philosophically and legally does not exist in jury trials.
We convict people based on "beyond a reasonable doubt". Which means, legally, you can have doubts about something being guilty, but if society deems them as unreasonably reached, you can still technically consider someone guilty.
Furthermore, "no doubt" allows people to be railroaded and even assuming 100% someone was known to do it, the number of cases involved would be a rounding error. It's not worth executing 100 people just to get at the 1 person you want dead.
- Witnesses are easily tamped with. False memories are a thing, but also just straight up paying people off, or someone is making it up for revenge.
- Photos can be edited.
- Videos can be edited.
- The system still admits polygraph tests, which are a proven pretend phony science.
- Finally, just plain unjust laws.