146 Withdrawal of charge
(1) The prosecutor may, with the leave of the court, withdraw a charge
before the trial.
(2) The withdrawal of a charge under this section is not a bar to any
other proceeding in the same matter.
(3) A Registrar may, in respect of any offence other than a category 4
offence, exercise the power under subsection (1) if the defendant
consents to the prosecutor withdrawing the charge.
If a person is indicted on criminal charges, but before trial the
state decides to "drop the charges," can the state later bring the
Yes it can (and not only the state, anyone can as private prosecution is allowed — unless that is seen as abuse of process). Double jeopardy defence only works if previous charges have evolved to acquittal/conviction. If they were dropped (withdrawn) before entering that stage, new charges can be laid again.
does the prosecution file a motion to "withdraw?" Can a consent decree
with the defense stop halt the case?
Yes, a formal application to withdraw is required. Unless the defendant consents to withdraw and it is not category 4 offence, approval by judge is needed.