get the goods on

[get the goods on] or [have the goods on] {v. phr.}, {slang} Tofind out true and, often, bad information about; discover what iswrong with; be able to prove the guilt of.

Tell the truth, Johnny.We know who your girl is because we've got the goods on you.

Thepolice had the goods on the burglar before he came to trial.