Very similar to a question posted several minutes earlier although from different counties, so maybe it's a coincidence today. Possession, sale, possession with intent to deliver, and manufacture of a controlled substance is both a violation of our state and federal criminal statutes and they CAN legally prosecute in both arenas. Dual prosecutions are extremely rare; they waste money and drug violations in either jurisdiction present significant penalties. Normally when the Feds "pick up" a drug case already filed in state court it is done by means of a superseding indictment in Federal Court. The parallel state charges are normally withdrawn by the DA upon motion to the court. Hopefully the affected person here has a very good criminal defense attorney with lots of experience in handling drug cases in Federal Court.
The interplay between state and federal sentencing is extremely complicated. It cannot be answered in just a few sentences on a site like this. Mr. Jones correctly points out that convictions in both state and federal court are rare. However, it can happen that a defendant is convicted in both federal and state court for the same drug offense. The defendant is well advised to retain an experienced federal defense attorney. This is definitely not a run-of-the-mill situation. Feel free to contact me on Monday for a free initial consultation if you have additional questions on a specific case in the Middle District of Pennsylvania.