My friend's release date from state prison was September but he was transferred last week to federal custody. Will he get credit for the time there?

my friend's release date from state prison was suppose to be september 10 but he was transfer last week to federal custody for a federal case. Is he still doing state time or did it stop his state time and he will have to come back and finish it after he deals with the fed rap? if he in federal custody is he getting credit for state or federal or what?

Answer: Wow, you are asking a very tricky question here. Generally when a state prisoner is transferred temporarily to federal custody for prosecution on a federal offense, he won't be entitled to credit on his federal custody time, but should be getting credit towards his state time. It may depend on how he got to federal custody. If he got there by what is called a "writ of habeas corpus ad prosequendum" then it is generally believed that the state has not released "primary custody" over the defendant and he is basically still in state custody. See Thomas v. Brewer, 923 F.2d 1361, 1366–67 (9th Cir.1991) (state retains primary jurisdiction over state prisoner transferred to federal custody by writ of habeas corpus ad prosequendum); see also United States v. Wilson, 503 U.S. 329, 334 (1992) (under 18 U.S.C. § 3585(b) , a defendant may not receive double credit for presentence detention time) 

18 USC § 3585 gives a defendant presentence custody credit, but only where it hasn't been credited against another sentence. This is going to be tricky for his attorney, but if he is sentenced on the federal case while still doing state time, you could ask the judge to run his federal time concurrently. There's no guarantee that the judge would do that, however. An experienced federal attorney can try to minimize his overall time.