People v. Hernandez, 2012 IL App (1st) 92841, an Illinois appellate court has held that the state must prove that a defendant knowingly used personal identifying information belonging to another person in order to convict on identity theft. Because the "defendant's knowledge was contradicted and not overwhelming," the charge was vacated and remanded for a new trial.
The defendant had used another person's social security number to obtain credit to purchase a vehicle. On the credit application, the defendant used both her own and the victim's SSNs, but the victim's was used for the credit check. When asked where she got the victim's SSN, the defendant said "that she 'made it up.'" It just so happened that the number belonged to a woman with the same first name, living in the same city who was alive and had good credit.
However, because the circumstantial evidence does not overwhelmingly prove the defendant's knowledge, the error was not harmless, and the case must be retried.