Why police lie under oath
On a historic note, Stalin's first, bloodiest purges were also governed by quotas and the heads of various departments of the secret police (NKVD) trying to one up each other, exerting pressure on their subordinates, and in the absence of judicial oversight. Stalin ended up replacing over-enthusiastic NKVD chiefs twice, and the last one, the one we remember the most and whose name, Beria, we come to associate with the oppressive force, was actually less brutal then the previous two (Yagoda and Ezhov).