Who would arrest a sitting President after impeachment in the House and conviction in the Senate? I would assume US Marshals.
The above article specifically stipulates a direct link back to Washington. Yet another article on this states that it leads directly back to the White House. A violation of law would normally be investigated under Holder, who has shown zero compunction towards ignoring and covering up all manner of illegal dealings no matter what Federal Agency is under question.
Both need removal from office for “high crimes and misdemeanors”. The least of which is violation of their oath of office, the greatest of which is treason for their support of radical Islamists over seas.
So yeah... Sorry if your vision doesn’t reach that far, but not all of us are quite that myopic.
An Impeached President does NOT go to prison or even to jail. He is simply removed from office.