Which amendment applies to this scenario? this amendment guarantees a trial before an impartial jury (one that favors neither side) ?

The following are all concern with the right to trial by jury; these are the 6th, 7th, and 14th. But the 6th is the main focus of the criminal justice system as it relates in the US. The 7th relates to civil hearings and the 14th to Due Process. Only the 7th has not been practical carefully to state laws.