Double Jeopardy [1] applies. If they had a better charge they should have brought it.

You can't be tried multiple times for the same incident.

[1] https://en.wikipedia.org/wiki/Double_jeopardy

In the US you can't be tried multiple times on the same charges for the same incident by the same government body.

You can be tried by both the federal and the state governments, separately, on the same charges (that is, on equivalent federal and state charges).

I think you can be tried for the same incident, by the same government body, on different charges.

> I think you can be tried for the same incident, by the same government body, on different charges.

Yeah, reading through the wiki on it, it appears you are correct. That usually does not happen just because it's costly.

Interestingly, when a case is dismissed without prejudice, for mistrial, or appeal, it can be retried again and again. Flowers endured six trials with 2 mistrials and 4 capital convictions and 4 appeals including an overturn by SCOTUS. He can still be prosecuted for the 7th time.

To be fair, there are absolutely situations where the court should be able to say "This particular trial was a shitshow and we're throwing it out, but there should still be a trial." Say, if the defendant has a malicious or incompetent defense attorney, it's fair that both they don't have to suffer the harm of that being their final chance to defend themselves but also the government doesn't have to just fully acquit them forever because their counsel sucked. Either alternative would lead to some pretty absurd incentives.

In all reality if you just threw a sandwich at a stranger you'd likely get away with it. Society only functions because people don't want to throw sandwiches for no reason.

Seemingly most things that are technically illegal are rarely enforced because it's just too much work and not severe enough to be worth it.

>Surely they could (will?) be charged with something though, right? I mean if I walk down the street now and launch a sandwich at a random stranger, it's some form of assault. "Attempt to cause bodily injury" is a bit much, but it's something.

Littering?

Another, similar case[0] was also brought, in Massachusetts some time ago. And there were, at least temporarily, some negative impacts on the defendant[1].

[0] https://youtu.be/zPx2t7xoF1k?t=390

[1] https://youtu.be/zPx2t7xoF1k?t=657