Colorado DUI - DWAI Study Predicts Re-offending Based On Blood Alcohol Level

January 14, 2013  


A 2010 study commissioned by the Colorado Division of Behavioral Health of the Colorado Department of Human Services asked the question of whether the Blood Alcohol Level p or BAC of a first DUI- DWAI offender was a predictor of a possible repeat offender.

DA's and judges in Colorado argue for harsher sentences and longer periods of treatment based on a driver's blood alcohol levels. Colorado enhances the sentences - even on first offenders - and I wondered why. This study - which I just happened upon - is used by the lawmakers to justify such a stern and punitive approach.

Here is a link to the study:


Here is a summary of the study:

The question was asked - are there BAC values that are consistently associated with a DUI offender's propensity to re-offend?

The Results of the Study

"Under a BAC of 0.150, first-time DUI offenders are less likely to re-offend and get a
subsequent DUI. As first-time offenders get arrested for DUIs with BACs at or above 0.150, they will begin to produce subsequent DUIs, and this will increase as a function of their BAC at initial arrest."

The Colorado Persistent Drunk Driver Committee

The Persistent Drunk Driver Committee (PDDC) was created in 1998 as a result of the enactment of the Persistent Drunk Driver (PDD) Act of 1998. One task of the committee was to explore the relationship between Blood Alcohol Content (BAC) and repeat DUI offenders.

When measuring DUI "recidivism" (re-offending after the initial arrest), the state has focused on "high BAC offenders." In Colorado in 1998 - the Colorado state legislature increased the penalties for high BAC and for multiple DUI offenders.


  • A persistent drunk driver (PDD) was defined a PDD as any person convicted of or whom had their driver's license revoked for two or more alcohol related driving violations,


  • OR

  • a person driving with a BAC of 0.20 or more.


The in 2006 Colorado passed the so called "per se law" which was set at the national level of 0.08 BAC. In addition the 2006 law defined the PDD BAC level to 0.17.

The state of Colorado takes the position that there are certain levels of blood alcohol that are associated with an offender's propensity to re-offend.

The Results Of The Study of the Question - Are there BAC values that consistently predict an offender's propensity to reoffend?

The study showed that BACs of 0.150 and above are more associated with recidivism than for those who don't re-offend; and that BACs of less than 0.150 are more associated with those who don't re-offend than with recidivism.

For all 43,403 study-subjects, an average BAC of 0.166 was observed. 7,720 (17.8%) were re-arrested within 5 years; 35,683 (82.2%) were not re-arrested. Those re-arrested produced a mean BAC of 0.171, whereas those without re-arrest had a mean BAC of 0.166. A highly significant difference was observed between First offender BACs as a predictor of DUI recidivism these two BAC group means.

The average first-offense BAC for those re-arrested (7,720) was 0.171. Of these recidivists, 6,625 (85.8%) subjects had 1 recidivism event, 744 (9.6%) had 2, and the remaining 351 (5.6%) had 3 or more. 50% of these persons re-offended within 1.9 years (700 days); 75% were re-arrested within 3.3 years (1211 days) and 90% were re-arrested within 4.3 years (1561 days).

Some Interesting Statistics On Repeat Offenders

If first-time offenders get re-arrested, they are most likely to get only one rearrest, and that occurring two years after their initial DUI arrest. If they get a second DUI re-offense (their 3rd DUI), they are most likely to get that re-arrest 3 years from their initial DUI arrest.

Higher BAC Levels - Says Colorado Study - Mean Greater Likelihood of Repeat DUI

The Persistent Drunk Driver Committee (PDDC) tasked this study to see what, if any relationship exists between BAC and recidivism in impaired driving offenders. It was observed that indeed, at the 0.150 level, Colorado offenders are more likely to produce recidivism; and that as the initial BAC level of first time offenders increases above 0.150, re-arrests will continue to be more associated with these offenders than for those not re-arrested.

The intent of the study was to justify taking a hard line against drunk drivers with higher BAC levels and explains the changes in the laws before and after the study was concluded.