preaching burglar
A humorous or ironic term for a burglar who, after breaking in, lectures the victim on how to prevent similar crimes. Often used in anecdotes or news stories.
They say a preaching burglar broke in and lectured the resident on crime prevention measures.
Compound of 説教 (sermon, preaching) and 泥棒 (thief, burglar). The exact origin is uncertain, but it likely arose from news reports or urban legends about unusual burglars.