Substantial evidence supports respondents' findings that petitioner was intoxicated and unfit for duty on the night of January 5, 1993, and that he failed to comply with a direct order to attend an alcohol rehabilitation program. Conflicting testimony purporting to explain petitioner's intoxicated appearance as due to a physical ailment raises issues of credibility unreviewable by the courts ( see, Matter of Berenhaus v Ward, 70 NY2d 436, 443-444). Petitioner's intoxication while off-duty but armed, his accompanying a fellow intoxicated officer as that officer menaced civilians with threats of bodily harm, and his prior conviction for driving while impaired supported respondents' order directing him to enter an in-patient rehabilitation program. Respondents had the authority to issue such an order ( see, NY City Charter § 434; Matter of Rivera v Beekman, 86 AD2d 1), and petitioner had no justification for refusing to obey it. In fact, petitioner never did attend an in-patient treatment center and the point is now moot.