A Parable for the Visitors

P witnessed A as he killed X.

P told A's boss B that A had done this act, but despite clear evidence proving A's crime, B believed A's lies, especially as A in concert with others discredited P.

P went to the boss of B, who believed B.

Z, the chief of service, was told of the matter, and asked B, and the boss of B, who confirmed their belief in the innocence of A. Z failed to investigate the matter any further than this.

The moral is that corrupt organisations allow the lazy and incompetent A's to get away with murder.