Motions To Exclude Or Limit Motions To Exclude Or Limit Evidence Of Retrograde Evidence Of Retrograde

ExtrapolationExtrapolation

“The generally accepted rate of burn-off is about one beer per hour, based on the “average man.” However, the “average man,” like the “average family” with 2.4 children, doesn’t exist; the only rates which have relevance are the rates of the person on trial. Absorption and elimination rates are affected by a myriad of factors.”

Using an oversimplified model, assume that there are 20 variable which contribute to the rate of absorption and that each of these variables has only 2

values. The mathematical formula for this model is 2n where n=20.

“Extrapolation back from the BAC at the time of testing to the BAC at the time of driving is an endeavor fraught with the danger of inappropriately bamboozling the jury into thinking that such an extrapolation can be anything close to accurate. The information which is usually available to the expert doing the extrapolation is woefully inadequate to make even an educated guess about a range of possible BACs.”

GUESSING BACKWARDS

Factors:1. Weight2. Gender*3. Physical Condition4. Metabolic Rate5. Time of Day6. When Something Was Eaten7. What Was Eaten8. How Much Was Eaten9. Time Drinking Started10. What Was Consumed11. How Much Was Consumed12. Drinking Pattern13. Altitude14. Point of Woman’s Menstrual Cycle15. Emotional State16. Whether Defendant Is An Alcoholic17. Inherited or developed tolerances18. Whether Medication Was Taken*19. What Medication Was Take20. When Medication was Taken

If you assume there are only 5 values per variable (518+22), the total number of possible combination is 3,814,697,265,629.

We can extrapolate in regards to which way each known factor, in

isolation, will affect absorption and burn-off, but prediction becomes more complicated each

time another factor is added to the equation. Very quickly, accurate extrapolation becomes

impossible.

2 4 8 16 32 64 128 256 512 10242048 4096 81921638432768

65536

131072

262144

524288

1048576

-100000

100000

300000

500000

700000

900000

1100000

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20

Number of Variables

Possible Number of Combinations

Mata v State of Texas (2001)13 S.W.3rd 1 (2001)

Evidence of Retrograde Extrapolation is inadmissible unless shown to be relevant and reliable. Judges are gatekeepers to weed out JUNK SCIENCE.

Scientific community is divided over validity of retrograde extrapolation. (Kelly/Frye Standard)

In order for it to have any relevance or reliability, expert must have evidence of at least the length of time of drinking, the time of last drink and the person’s weight. Since there are so many variables (At least 20) The more factors known to the expert, the more likely that the application of this theory will be reliable.