Even the President or the Supreme Court Justice has no power to reverse a verdict without the proper support of the rules of the law or equitable basis for such drastic measures.
The force required to pull a trigger is not rocket science, but a concept and a feel a layperson can better grasp simply by pulling the trigger using his own hand. In this scenario, the help of an expert witness is minimal because the pulling of a trigger requires no prior training in the underlying science or fundamental understanding of the mechanism behind the trigger mechanism of a gun.
Even a physics Ph.D. could not convey effectively to the jury how much force is needed to pull a trigger because a pure number in this case is meaningless to the jury. In contract, the direct pulling of the trigger gives the jury undisputed feel and understanding of the amount of force needed to pull the trigger.
In addition, the issue here is not what mental state Officer Liang was in or whether his mental state affected his finger strength to pull the trigger. Rather, the issue is that whether the force needed to pull the trigger is so huge that without using a finger, Mr. Liang could have pulled the trigger! What the juries experienced themselves by trying to pull the trigger was that even with a finger it was very hard to pull the trigger. Thus, it made no sense to them regarding Mr. Liang's claim that his finger was not on the trigger before his gun fired a shot. That statement was treated as a complete lie.
Mr. Cao fails as an attorney to present a legitimate case to support his accusation of improper handling of the evidence by the jury. As the saying goes, the proof of the pudding is in the eating. Along the same line, the proof of the killing is in the pulling!
