The “trier of facts” always decides all relevant disputed factual issues. By contrast, the trial JUDGE always decides all LEGAL issues.
WHO is the “trier of facts”?
Ordinarily, the JURY is the “tier of facts,” but in some cases (i.e., in cases where there is no jury), the TRIAL COURT must act in the separate role of the jury of fact-finder to resolve disputed facts, in addition to its normal role as the judge (to resolve all LEGAL issues).