One major factor on that is going to be the timing of the federal offense and new state charge. I can't tell from what you've said whether he just got arrested after he was put on probation, but the offenses actually occurred before he was put on probation (meaning they didn't arrest him right away and instead issued warrants for him), or whether those offenses happened after he was placed on probation. There's a big legal difference there: if it's the first situation, they may be able to do concurrent probations, but if it's the second, the new offenses would be violations of his probation, and would be both grounds to revoke the existing probation and a good reason not to give him probation at all on the new charges..
Sort of. If the feds have him, they are not going to release him to anyone. The state cases that were picked up by the feds will be dismissed after he's sentenced federally. It's important that there be an active warrant on the probation violation. This will allow him to get back time credit on that case for all the time he serves federally.
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