There's a difference between accusation and punishment though — we were talking about those accused, not those convicted.
(Besides which, I don't think murderers ought to be imprisoned for lengthy sentences, only long enough for an appeal and if that falls through then immediately executed.)
I dunno. Government has the duty to protect the governed, employing reasonable measures. We see it every day. And we benefit from it.
Protecting the governed
can be applied to say that the need/right of the many outweigh the need/right of the few, or the one, and therefore be used to invalidate inherent rights — and that way leads to very, very bad things.
Without morality, then, we are lost. That is the key. And you are correct. But morality is not completely lost among the tens of thousands of officers appointed to the courts. I have seen exceptions. But the good still out-number the bad. The traction to oppose such wonton disregard for uprightness is often weak among peers and superiors. But egregious violators are yet prosecuted. Humans are imperfect...but still tend toward perfection.
With regard to accused or convicted....accused have the right to be tried by jury. It is incumbent upon the state to make certain that the person accused and arrested is the same person before the court, later in the process. That requires absolute certainty as to identity. The accused is compelled to satisfy the court of identity....especially so that no innocent person be punished. Non- compliance with that necessary and proper safeguard compels custody of the accused.