What is "criminis"

Usage examples of "criminis".

And look at the strange folio over there: Praxis criminis persequendi by Simon de Colines, 1541.

Let us not forget that for more than two centuries we have been particeps criminis, and should have been in as great a difficulty as the Americans now are, had we had the negro population on our own soil, and not on distant islands which could be legislated for without affecting the condition of the mother country.