An appeal, sure.
But I doubt they’re going to get a mistrial on it. Dude is guilty as hell. Probably going to lead to reduced sentencing, though. (All though that’s still gonna be at “you’re fucked” levels,)
Edit: even if there is a mistrial, they’ll certainly be allowed to retry.
I dunno.
Maybe they like the propaganda of trump getting shot at?
Their legal strategies are written in crayon, so maybe they just think a sentence of a second lifetime is meaningful.