system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: How can it be possible to be declared innocent of a crime when there is video and audio of the event?
gpt
The point isn't to be declared "innocent", more "not guilty". The distinction is important because innocent means "we know he didn't do it" which is nearly impossible to know. 

"Not guilty" means there's not enough evidence to convict someone of a crime.