[If at any time before trial a defendant moves to suppress, or during trial makes timely objection to the admission of evidence consisting of (a) a confession or other incriminating statements alleged to have been made by the defendant to police authorities, (b) the fruits of a search, or (c) witness identification, the trial court shall conduct an evidentiary hearing outside the presence of the jury and at the conclusion thereof shall enter into the record findings resolving the essential issues of fact raised by the motion or objection and necessary to support the ruling. If supported by substantial evidence the factual findings of the trial court shall be conclusive.]