How Do Prior DUI Convictions (Within 10 Years) Affect New DUI Charges in Idaho?

When it comes to drunk-driving law, Idaho is decidedly forward-looking: what you did up to a decade ago can transform today's arrest from a “simple” misdemeanor into a mandatory-jail offense—or even a felony. Below is a direct, plain-English guide to how Idaho's 10-year “look-back” rule works, what penalties stack up with each repeat conviction, and why a prior record sharply raises the stakes.

1. Idaho's 10-Year Look-Back Rule Explained

Idaho Code § 18-8005 treats any prior DUI conviction—or guilty plea—entered in the 10 years before your new arrest as an “enhancing” offense.

• Clock starts on the date you were found or pled guilty, not the arrest date.

• Out-of-state DUIs count, as long as the other state's law is “substantially conforming”—virtually every U.S. DUI statute qualifies.

• Withheld judgments, and excessive-BAC DUIs all count the same.

If the prior offense is outside the 10-year window, the new charge is sentenced as a first offense—but prosecutors still see the record—and judges can consider it in discretionary sentencing.

2. Penalties Escalate Quickly: First, Second, Third Offenses

High-BAC (“Excessive”) and Aggravated Cases

• Excessive DUI (BAC ≥ 0.20 %) even as a first offense carries up to 1 year jail, up to $2,000 fine, and a 1-year license suspension.

• Second Excessive DUI within 5 years is an automatic felony, punishable by up to 5 years prison and at least 1-year license loss.

• Aggravated DUI (serious bodily injury) starts as a felony regardless of prior record, with prison exposure up to 15 years and mandatory jail time.

3. Why Prior Convictions Trigger Mandatory Minimums

Legislators assume repeat offenders pose a higher public-safety risk. To remove judicial discretion, Idaho imposes mandatory minimum jail and longer license suspensions once a prior DUI shows up within 10 years. Courts have no authority to suspend these minimum days—though they may allow work-release or jail-alternatives where county programs exist. Also, in Ada County with the new Judges that have been appointed, there has been a huge change in sentencing for second DUIs. Often the Boise Judges are sentencing second offenders to weeks of straight jail time, especially if treatment has not been completed prior to entry of plea and sentencing.

4. License Consequences Get Harsher

• First DUI: 90-day suspension, but restricted driving is possible after 30 days.

• Second DUI: Full 1-year hard suspension—no driving at all regardless of hardship.

• Third DUI: Minimum 1-year absolute suspension, and the Court can order it be continued up to 5-years.

5. Collateral Fallout of a Felony DUI

Crossing the line from misdemeanor to felony—typically on the third DUI (or second excessive)—triggers consequences well beyond prison exposure:

1. Firearm Rights: Lost until civil rights are restored.

2. Professional Licenses: Nurses, teachers, CDL holders, and pilots face automatic reviews.

3. Travel and Immigration: Felony records complicate visas and border entries.

4. Repeat-Felon Enhancements: Any future felonies carry higher sentencing ranges.

6. Defending a Repeat-Offense DUI: Key Pressure Points

Because sentencing enhancements rely on certified prior convictions, defenses often focus on procedural integrity:

• Out-of-State Priors: Was the statute “substantially conforming”? A nuanced difference (e.g., no actual-physical-control element) can knock out the enhancement.

• Guilty Plea Validity: If the earlier plea lacked a clear advisement of rights or counsel, a court can deem it unconstitutional for enhancement purposes.

• Timing Errors: Arrest date vs. conviction date sometimes moves a borderline prior outside the 10-year window.

Successful challenges can revert a second or third DUI back to first-offense penalties—a huge reduction in jail time and license loss.

7. Practical Takeaways

1. The 10-year look-back dominates Idaho DUI sentencing. One old conviction can double or triple penalties.

2. Second offense? Mandatory 10 days jail and a full year off the road—no exceptions.

3. Third offense? You're in felony territory with prison on the table.

4. All priors count—Idaho, other states, juvenile adjudications, “excessive” DUIs.

5. Early record review matters: Spotting technical flaws in past convictions may defuse today's enhancement.

Facing a repeat DUI charge means jail time and license loss are virtually baked in. Understanding the enhancement rules—and examining every prior case for possible challenges—can drastically reshape the outcome. Stay informed, act quickly, and treat any prior conviction within the last decade as a flashing red warning light: the stakes just got a lot higher.