Haw. R. Penal P. 8

(a) Joinder of offenses. Two or more offenses may be joined in one charge, with each offense stated in a separate count, when the offenses:

(1) are of the same or similar character, even if not part of a single scheme or plan; or

(2) are based on the same conduct or on a series of acts connected together or constituting parts of a single scheme or plan.

(b) Joinder of defendants. Two or more defendants may be joined in the same charge:

(1) when each of the defendants is charged with accountability for each offense included in the charge;

(2) when each of the defendants is charged with conspiracy and some of the defendants are also charged with one or more offenses alleged to be in furtherance of the conspiracy; or

(3) when, even if conspiracy is not charged and all of the defendants are not charged in each count, the several offenses charged:

(i) were part of a common scheme or plan; or

(ii) were so closely connected in respect to time, place and occasion that it would be difficult to separate proof of one charge from proof of the others. (c) Failure to join related offenses.

(1) A defendant who has been tried for one offense may thereafter move to dismiss a charge in a subsequent trial for any related offense, as defined in Rule 13(b)(1), unless the related offense is one which was pending in court prior to the commencement of the first trial. The motion to dismiss must be made prior to the second trial, and shall be granted unless the court determines that because the prosecutor did not have sufficient evidence to warrant trying the offense charged in the second trial at the time of the first trial, or for some other reason, the ends of justice would be defeated if the motion were granted.

(2) Entry of a plea of guilty or nolo contendere to one offense does not bar the subsequent prosecution of a related offense.