first of all it's not lack of evidence, it is evidence itself. if the camera is not working that's tampering with evidence and is a good indication of guilt.

second of all if you can have laws like felony murder you can sure as shit have this. if you commit a felony (like a robbery), don't hurt anyone, and a cop murders a random person in response because they're trigger happy pigs, you can be held responsible for the murder as if you committed it yourself.

my suggestion is far more reasonable compared to that: if you kill someone you better have evidence that it wasn't foul play, because guess what, that's what everyone needs to do. we don't just allow people to kill and go free, and cops shouldn't be exempt.

Should be at least streamed to a server not controlled by the police, including things like charge levels so they can't claim "oh whoops, it ran out of charge!". A specific organisation within the judiciary, perhaps?

This way they're gonna need to get far more creative in concealing video.

And if you're found to do something that is concealing evidence, well that's a crime by itself

Hard agree. Its a non negotiable part of the job. I dont know that it would work to say absense of footage is evidence of wrongdoing, but its definitely enough to fire someone. Accountability would keep cops in line. Currently there is VERY little real systematic accountability for cops, in any situation.

Can't we just embrace adverbification and agree to write "suddenly"?

People aren't saying it because they're language scholars, it's because they misheard the proper modern usage. So it goes for many language shifts.