For better or worse, the only admissible evidence going forward will probably be either completely physical or originated in attestation-capable recording devices, i.e. something like a "forensics grade" camera with a signing key in trusted hardware issued by somebody deemed trustworthy.

Given the obvious personal safety upsell ("our phone/dashcam/... produces court-admissible evidence!"), I think we'll even see this in consumer devices before too long.

Trials have rules for evidence. You can't just pull out some footage out of nowhere. Where did that come from? From what camera? What was the chain of custody on its footage? Etc.

Yes, that is a major worry of mine, too. CCTV evidence is worth nil now (could be generated in whole or part), and even eye-witness testimony can be trusted (sure, a witness may think they saw the alleged perpetrator, but perhaps they just saw an AI-generated video/projection of someone).

MS13 was literally tattooed on his knuckles!

Multiple data sources, considering the trustworthiness of the source of the information, and accountability for lying.

You might generate an AI video of me committing a crime, But the CCTV on the street didn't show it happening and my phone cell tower logs show I was at home. For the legal system I don't think this is going to be the biggest problem. It's going to be social media that is hit hardest when a fake video can go viral far faster than fact checking can keep up.

By having people also testify to authenticity and coming down like the hand of God on fakers, the same way we make sure evidence is real now.

If it means anything, I have a 1990 Almanac from an old encyclopedia that warns the exact same thing about digital photo manipulation. I don't think it really matters at this point