Can you provide the sentence in which you might use "ventilate", Mateusz? I sometimes hear people use "vent" when they're referring to relieving emotional pressure by talking. I sure don't recall ever hearing or reading the word "ventilate" as a synonym for "disclose".
"to ventilate" does not mean "to disclose confidential information or a secret."
"To ventilate" means to let air out of an enclosed space and new air in. It can also mean "to breathe," which also involves an exchange of air. It's from the Latin word for wind.
In relation to crime, there is a humorous use of "ventilate." Since one way to provide ventilation is to poke holes in something (like a box with a captured animal in it), shooting some many times, which puts many holes in his body, is sometimes called "ventiliating" him. But this doesn't have anything to do with uncovering or disclosing criminal records or the particulars of a crime that has been committed.