Is a police officer liable in tort merely for failure to take affirmative action to assist or protect another?

It is true that in many situations, a person is "not liable in tort merely for failure to take affirmative action to assist or protect another unless there is some relationship between them which gives rise to a duty to act. [Citations.]" (Williams v. State of California (1983) 34 Cal.3d 18, 23, 192 Cal.Rptr. 233, 664 P.2d 137.) Such a relationship exists when a law enforcement officer's promise or conduct induces detrimental reliance by the plaintiff. ( Id. at p. 25, 192 Cal.Rptr. 233, 664 P.2d 137.)