I am not a lawyer or an expert of any kind, but I believe it happens fairly regularly. Regularly enough that Commodore's suggestion that a mistrial on 10/18 charges for Manafort means the whole prosecution is illegitimate is very very stupid.
Prosecutors will re-evaluate their case, gauge the likelihood of success, and then decide whether to re-try the case. When they have a single hold-out - which, I mean, the holdout still convicted on 8 counts, so I don't think anyone ought to hold that against the person - I'd say the move would almost always be to re-try the case.
UNLESS, as they have here, there are some convictions. The prosecutors have 8 felony counts to sentence Manafort on, and since he wasn't acquitted on the other charges, his conduct which led to those charges can be argued by the prosecution and factored in by the judge when determining the length of his sentence.
Seeing as they have up to 80 years to work with, the prosecution might simply decide it's not worth the effort of another trial and just try to stick it to him at his sentencing. Especially since he is already facing another trial in a different court.
As to this, I'm really not sure. Maybe
@metalhead or
@JollyRoger can speak to it.
This argument is always made when high profile cases end in a hung jury. It happened in the Bill Cosby case, and his first jury was hung on all counts. They found another jury and got their conviction the second time around.
The argument always fails, because the system recognizes that there is no such thing as an unbiased juror. They can find jurors who are ignorant about the evidence going in, even in a high profile trial, which is really what matters and is the best you can hope for under the circumstances.
It does leave the door a little more open for an appeal of a jury verdict than it otherwise might be; jury verdicts are almost never overturned as a matter of principle. But that's about it.