That LEO's conduct was outrageous and totally unprofessional! It is to be hoped that his department's internal affairs procedures will bring about the appropriate conclusion.
Our system of justice is dependent upon competence and adherence at all levels to those individual rights guaranteed by the United States Constitution. Unethical police officers, unscrupulous prosecutors, incompetent defense counsel, and unqualified judges are all threats to the entire system. It is fortunate that in each category they are few and far between -- the unfortunate exception rather than the general rule. Nonetheless, the damage that even one of them at any of the levels can inflict is enormous and extends beyond those immediately involved by eroding public confidence in the entire system.
Our system of justice may not be perfect, but it is still the best system yet devised by humankind. However, as the old maxim states, "Eternal vigilance is the price of liberty."