BILLINGS, Mont. -

More than half of all sexual offenders registered in Montana don't have a designation that indicates how likely they are to re-offend and sets requirements for checking in with authorities.

A review by The Billings Gazette found 59 percent of sex offenders registered in May and June and 58 percent of those registered in August didn't have a tier designation.

Since 1997, convicted sexual offenders are supposed to be given a tier 1, 2 or 3 designation, identifying them from least to most likely to re-offend. Out-of-state offenders and those convicted before 1997 are treated as though they're tier 1 offenders.

The 2013 Legislature passed a bill that gave District Court judges the authority to assign a tier level to an offender after sentencing. Since then, 200 offenders have been evaluated and assigned tier levels.