Section 40(1)(b) of the Criminal Procedure Act 51 of 1977 contains only four jurisdictional facts required for a lawful arrest without warrant: (i) the arrestor must be a peace officer; (ii) the arrestor must entertain a suspicion; (iii) the suspicion must be that the suspect committed a Schedule 1 offence; and (iv) the suspicion must rest on reasonable grounds. There is no fifth jurisdictional fact requiring the arresting officer to consider less invasive alternatives to arrest. Once these four jurisdictional facts are established, a discretion arises whether to arrest. The discretion must be exercised properly (in good faith, rationally, not arbitrarily, and for the purpose of bringing the suspect to justice), but the proper exercise of discretion is not a jurisdictional fact. The onus of proving the four jurisdictional facts rests on the defendant (the Minister). However, once these are established, the onus of proving improper exercise of discretion rests on the plaintiff. The purpose of arrest is to bring the suspect before court within 48 hours; it is for the court (not the arresting officer) to then determine bail and detention. In cases involving serious Schedule 1 offences, it will seldom be irrational for a peace officer to effect an arrest.