State v. Kenneth Nixon, 291 P.3d 1154

Nixon charged with DUI fourth or subsequent offense on Sept. 13, 2010, with prior qualifying offenses in 1992, 1999, and 2009.
On Apr. 25, 2011, Nixon moved to dismiss alleging the 1992 conviction was constitutionally infirm and could not be used for enhancement.
Nixon submitted an affidavit asserting he was indigent, not represented by counsel in 1992, not advised of right to counsel, and did not knowingly waive that right.
The 1992 conviction occurred in Ravalli County Justice Court before Judge Sperry; docket and notes did not clearly reflect counsel or waiver, though Nixon alleged lack of counsel.
The district court held an evidentiary hearing (May 18, 2011) with Judge Sabo testifying about intake procedures and missing explicit waiver in the docket; the court denied the motion (May 19, 2011).
Nixon appealed the denial; the Montana Supreme Court affirmed, applying the collateral-challenge framework for prior convictions used for sentence enhancement.

Issue	Plaintiff's Argument	Defendant's Argument	Held
Whether the 1992 DUI conviction is constitutionally infirm for enhancement	Nixon asserts lack of counsel and no waiver, constituting infirmity	State contends evidence is ambiguous; burden remains with Nixon to prove infirmity	No; Nixon failed to prove infirmity by a preponderance; district court not clearly erroneous

Haas v. State, 265 P.3d 1221 (Mont. 2011) (affirmative evidence required to overcome regularity presumption; preponderance standard)
Maine v. State, 255 P.3d 64 (Mont. 2011) (three-step framework for collateral challenges to prior convictions)
Chaussee v. State, 259 P.3d 783 (Mont. 2011) (defendant bears burden to show infirmity; not all ambiguous records suffice)
Howard v. State, 59 P.3d 1075 (Mont. 2002) (unequivocal sworn statements of lack of counsel can establish infirmity)
Walker v. State, 188 P.3d 1069 (Mont. 2008) (affidavits alleging lack of counsel can prove infirmity; weigh credibility of statements)
Chesterfield v. State, 262 P.3d 1109 (Mont. 2011) (affirmative evidence required; ambiguous records insufficient)