Jenny's Dad, Jasper, committed suicide While under investigation on being suspected of taking a bribe, and Jenny blamed La Grenouille for his death and believed he was responsible for the allegations against him.
However, In one episode His fingerprints are on a bottle and glass in Jenny's study. Abby runs them and finds he was deceased. But when questioned by the FBI in the killing of La Grenouille, Abby makes a comment that someone might havcircumstantial evidence existe been trying to confuse her. Although this is the info from the show, Who really knows. Hope that answers that for ya. :)