Anyone in the act of committing a crime, may be arrested by any person present, without a warrant.
HRS § 803-3
Attorney General Opinions
A police officer may arrest without a warrant if the police officer has probable cause to believe an offense is being committed in the police officer's presence, even though it be a violation. Att. Gen. Op. 76-4.
Arrest without warrant, legal. 14 H. 586. Police officer may arrest for a misdemeanor without warrant if, based on personal knowledge, police officer has probable cause to believe offense is being committed in police officer's presence. 56 H. 383, 538 P.2d 320. This authority extends to misdemeanors. 56 H. 675, 548 P.2d 268.