Griego

*571 Opinion

The state initiates civil proceedings to declare a person a sexually violent predator (SVP). In exchange for his deposition testimony on certain matters, he receives transactional immunity for those matters and “any of the matters that he may testify to.” Here we conclude that he may not be prosecuted for a crime relating to his deposition testimony.

Facts

The People initiated proceedings to declare petitioner Leonard Griego an SVP. (Welf. & Inst. Code, § 6600 et seq.) While the petition was pending, the People noticed his deposition.

Griego, claiming the shield of the Fifth Amendment, moved to quash the deposition or, in the alternative, for a protective order. In response, the People represented to the trial court that they would limit their inquiry to: (1) Griego’s current mental illness; (2) his past charged criminal conduct; and (3) an alleged sexual assault upon his half brother. The People asserted that this information was relevant because it would be used by mental health professionals to diagnose and treat Griego for a personality disorder. The deputy district attorney acknowledged that the Fifth Amendment was implicated. He assured the court, however,…