What is the test for determining whether a statement was illegally obtained?

" ' "[W]e accept the trial court's resolution of disputed facts and inferences, and its evaluations of credibility, if supported by substantial evidence. We independently determine from the undisputed facts and the facts properly found by the trial court whether the challenged statement was illegally obtained." [Citation.]' [Citation.]" (People v. Enraca (2012) 53 Cal.4th 735, 753.)