Does that mean that every single conviction from before the days of forensic evidence is necessarily invalid?
If the argument is that forensic evidence decreases uncertainty, well, it certainly doesn’t eliminate uncertainty.
Convicting anyone of anything is a slippery slope. The only way to be truly sure is to never do it, ever.
The case was a shooting. It seemed remarkable they had neither a gun, spent cartridge cases, blood, flesh, wounds, or anything in the way of physical evidence.