Witnesses of the crime are sought, but never found.

A citizen would consider himself dishonoured if he were to give up his comrade to the natural enemy of the nation.

The murdered man himself, if he could be brought to life, would swear he had seen nothing of the affair.

The Government is not strong enough to force the witnesses to say what they know, or to protect them against the consequences of their depositions.

This is why the most flagrant crime can never be proved in the courts of justice.
Supposing even that a murderer lets himself be taken, that witnesses give evidence against him, and that the crime be proved, even then the tribunal hesitates to pronounce the sentence of death.
The shedding of blood--legally--saddens a people; the Government has no fault to find with the murderer, so he is sent to the galleys.