Colorado’s supreme court denied Attorney General Phil Weiser’s request to reconsider a decision that could throw out hundreds or thousands of criminal sentences.

The court in September decided that it was illegal for convicted defendants to receive sentences that include both prison and probation in the same case. Defendants convicted by jury will be minimally affected, only requiring new sentences.

However, cases involving plea deals – which, as The Denver Post reports, comprise 95% of all criminal cases – are invalid. That could mean prosecutors must start over in an as-yet-undetermined number of cases.

“Given the passage of time, victims who thought the case was resolved will now be forced to consider whether to face their assailants and testify, and prosecutors will need to prepare for trial years after the sex offenses occurred,” Weiser wrote in his request.

At least four of the state’s 22 judicial districts have employed the now-illegal sentencing. Prosecutors used the tactic largely against alleged sex criminals to ensure lifetime supervision after their release.

“Admitted sex offenders in some cases could be abruptly released into the community without completing treatment,” Weiser’s petition continued. 

The attorney general’s office found 78 such cases occurred in 2018. The Supreme Court is allowing an unlimited lookback window to challenge sentences.