What happens if the State doesn't file charges in time?

The consequence is release from custody, not termination of the case. Those are different outcomes and the difference matters.

If the deadline passes without a charging document, counsel can move for release. The State may respond by showing good cause for the delay, and courts do grant that in some circumstances.

What release under this rule does *not* mean: that the case is over, that charges can't be filed, or that you won't be arrested again on the same conduct. The State retains its ability to file within the applicable limitations period, and people are frequently surprised months later.

There's a separate question worth asking when charges aren't filed promptly, which is why. Sometimes it's volume. Sometimes it's a problem with the case — a witness who won't cooperate, a lab result that hasn't come back, an issue with the stop. That interval is often when a case can be resolved before it's ever formally filed.