P.R. Laws Ap. tit. 34A, § 1–A, Rule 2.4
(a) By a peace officer.— A peace officer may apprehend without prior court order when:
(1) There are reasonable grounds to believe that the minor has perpetrated an offense in his presence. In this case, the apprehension shall be performed immediately after the perpetration of the offense or within a reasonable time thereafter.
(2) The apprehended minor has perpetrated Class II or III offense, not in his presence.
(3) There are reasonable grounds to believe that the minor has perpetrated a Class II or III offense, independent from the fact that said offense might have been perpetrated or not.
In cases of clause (1) where peace officer participates, if said peace officer cannot perform the apprehension immediately or within a reasonable time after the offense was perpetrated, he should refer the case to a peace officer especialized in minors affairs, or to the office of the Prosecuting Attorney for Minors’ Affairs directly, for the proper investigation.
(b) By private person.— A private person may apprehend a minor:
(1) For an offense perpetrated or attempted in his presence. In this case apprehension must be performed immediately.
(2) When a Class II or III offense had been perpetrated and the private person had reasonable grounds to believe that the apprehended minor perpetrated it; said private person should take the minor to a peace officer who will proceed as if he would have performed the apprehension and in turn, without unnecessary delay, the peace officer will take the minor before a judge, as provided by these rules.