The philosopher Hegel theorized a dialectical process: a thesis is proposed, an anti-thesis is presented, and the collision of the two results in a synthesis.
American jurisprudence is a unique, dialectical process, particularly in the realm of criminal justice. The legislatures make the laws with respect to what's legal - and what's not. The executive branches of the state and federal governments enforce the laws. And the judiciaries act as checks and balances for the citizens to ensure that the other branches do not trample the rights of the citizens in the oft-competitive profession of law enforcement.
The efforts of all of the above must be in conformity with the Bill of Rights of the Constitution of the United States and the respective state constitutions. It is here that good defense counsel uses the rights afforded to citizens under the respective constitutions and statutory protections to ensure that justice is done.
The state makes its allegations. Defense counsel challenges the bases of the allegations and the credibility of the testimony and evidence presented. And the trier of fact determines whether or not the state has met its burden of proving the defendant guilty by the high and heavy burden of proof beyond a reasonable doubt. The verdict is the synthesis.
The system works when everyone does their jobs. Or does it?