It is the 5th amendment which states that a person cannot be tried twice for the same crime. It is referred to as double jeopardy.
5th amendment
The 5th amendment
5th Ammendment-prohibits Double Jeopardy.
The 5th Amendment - prohibits double jeapordy.
the 6th amendment
The 4th Amendment.
the person can not be tried for the same crime twice.
The double-jeopardy clause
There exists a provision in the U.S. Constitution, whereby a person cannot be tried for the same crime twice once found not guilty of that crime. This so-called double jeopardy clause protects an individual against abuse by frivolous accusations, and sets a high bar with regard to evidence in the charging of crimes.
The 5th amendment
Fifth Amendment (Study Island)
The 5th Amendment states that a person can be tried for a serious federal crime only if he or she has been indicted (charged, accused of that crime) by a grand jury. No one may be subjected to double jeopardy - that is, tried twice for the same crime. All persons are protected against self-incrimination; no person can be legally compelled to answer any question in any governmental proceeding if that answer could lead to that person's prosecution. The 5th Amendment's Due Process Clause prohibits unfair, arbitrary actions by the Federal Government.
I am not sure what amendment it is in, but I do know what it is called. It is call Double Jeopardy. This concept, as you said, means that a person, if found NOT GUILTY for a crime, can't be tried for that same felony.