have a case
have a case (against someone or something)
To possess a significant amount of incriminating evidence (against someone or something), as could be presented in court. With her testimony, now we really have a case. My lawyer says we have a case against our landlord.
Farlex Dictionary of Idioms. © 2015 Farlex, Inc, all rights reserved.
have a case (against someone)
to have much evidence that can be used against someone in court. Do the police have a case against John? No, they don't have a case.
McGraw-Hill Dictionary of American Idioms and Phrasal Verbs. © 2002 by The McGraw-Hill Companies, Inc.