What is the test for determining whether a police officer made a false promise to a defendant?

Where the evidence before the trial court is conflicting, this court "must `accept that version of events which is most favorable to the People, to the extent that it is supported by the record.'" (People v. Hogan (1982) 31 Cal.3d 815, 835, disapproved on other grounds in People v. Cooper (1991) 53 Cal.3d 771, 836.) The record here supports the trial court's implicit determination that no officer made a false promise to defendant in order to induce him to admit ownership of the drugs.