The admission or confession of a defendant needs legal corroboration.

This corroboration is often very difficult to find, and frequently cannot be secured at all.

This provision of the statutes is doubtless a wise one to prevent hysterical, suicidal, egotistical, and semi-insane persons from meeting death in the electric chair or on the gallows, but it often results in the guilty going unpunished.

Personally, I have never known a criminal to confess a crime of which he was innocent.

The nearest thing to it in my experience is when one criminal, jointly guilty with another and sure of conviction, has drawn lots with his pal, lost, confessed, and in the confession exculpated his companion.
In the police organization of almost every large city there are a few men who are genuinely gifted for the work of detection.