Trial court should have considered the evidence received at the preliminary hearing in determining whether sexual battery was a lesser included offense to forcible sexual penetration under the accusatory pleadings test. Ortega was charged with sexual penetration by force (Pen. Code, § 289, subd. (a)(1)(A)). The jury found him not guilty of that offense, but guilty of the lesser included offense (LIO) of assault with intent to commit sexual penetration by force (Pen. Code, § 220, subd. (a)(1)). On appeal he challenged the trial court’s failure to instruct on the LIO of sexual battery (Pen. Code, § 243.4, subd. (a)). Held: Reversed. A trial court must instruct sua sponte on any lesser included offense that is supported by substantial evidence. An offense is an LIO if either the statutory elements of the greater offense, or the facts alleged in the accusatory pleading, include all of the elements of the lesser offense. Here, the allegation of forcible sexual penetration in the information tracked the language of the statute. But the accusatory pleading cannot be examined in isolation. Due process requires that the facts derived from the preliminary hearing be factored into the accusatory pleading analysis. Forcible sexual penetration is the act of penetrating the genital or anal opening by any foreign object or substance, which includes any part of the body except a sexual organ. Testimony at the preliminary hearing identified appellant’s fingers as the only object supporting the greater charge. “Defendant’s due process right to rely on that testimony extends not only to his right to prepare a defense but also to his right to have a jury decide all necessarily included lesser offenses identified by that testimony.” The court’s failure to instruct on sexual battery was prejudicial under the Watson test.