Attacking and defending widmark calculations

• Author: Don Bartell/Mary Catherine McMurray/Anne ImObersteg
• Pages: 275-290

10-1

CHAPTER 10

ATTACKING AND

DEFENDING WIDMARK

CALCULATIONS

I. GENERAL POINTS

A. History and Use of Widmark

§10:01 Professor Widmark’s Treatise

§10:02 Use of Widmark in Trial

B. Widmark and the Per Se Laws

§10:10 Per se Laws Encourage Use of Widmark

§10:11 Examples of per se Statutes

§10:12 Defense Use of Difference in Statutes

II. ATTACKING WIDMARK CALCULATIONS

A. The Secret to Winning Any Trial

§10:20 Deal With the Predominant Problem

§10:21 Identifying the Predominant Problem

§10:22 Solving the Predominant Problem

B. The Predominant Problem in Drunk Driving Cases

§10:30 Presumption That the Defendant Is Guilty

§10:31 Widmark Calculations and the Predominant Problem

C. Attacking the Calculations

§10:40 Typical Presentation of Widmark Calculations

§10:41 Expose the Charade

§10:42 Ask What the Formula Is

§10:43 Ask Whether the Expert Has Read Widmark

§10:44 The Widmark Variables

§10:45 Cross-Examining on the Widmark Variables

§10:46 Checklist for Attacking Widmark Calculations

D. Widmark Calculations in Breath Cases

§10:50 Calculations Attack Defendant’s Veracity

§10:50.1 Challenging Calculations that Attack the Defendant’s Veracity

ATTACKING & DEFENDING

WIDMARK CALCULATIONS

Attacking and Defending Drunk Driving Tests 10-2

ATTACKING & DEFENDING

WIDMARK CALCULATIONS

§10:51 Breath Machine Assumes a Partition Ratio

§10:52 Right to Attack Breath Machine’s Accuracy

III. DEFENDING WIDMARK CALCULATIONS

§10:60 Keep the Presumption of Guilt Alive

§10:61 Consider Not Using Widmark

§10:62 Explain the Widmark Calculations

§10:63 In Breath Cases Avoid Partition Ratios

IV. RETROGRADE EXTRAPOLATION—A DUBIOUS PRACTICE

§10:70 The Problems with Retrograde Extrapolation