A guard observes three people wearing identical gang-affiliated clothing standing together near a posted-private property line. They have not violated any law. May the guard detain them based on appearance alone?

Explanation

Reasonable suspicion (for detention) and probable cause (for arrest) both require articulable facts indicating criminal activity (In re Tony C. (1978) 21 Cal.3d 888). Clothing, group association, or perceived affiliation without observed unlawful conduct does not, by itself, establish either standard. The guard may engage consensually, observe, document, and call police if conduct escalates, but cannot lawfully detain on appearance alone. Options (a), (c), and (d) misstate the law; arbitrary durations and owner consent do not cure constitutionally insufficient cause.