He will face charges in one state and if found guilty be given a harsher penalty than someone not on parole. He will enter this state's prison system with a detainer. Once that is completed he will most likely be picked up by a sheriff from the state where he is on parole. He will be held until meeting with a judge from that jurisdiction. The bureau of prisons will give input as to what they would want in the way of more time. It will usually be the amount of time that the parole erased.