California DUI attorneys representing clients charged with DWI, drunk driving or driving under the influence DUI California Your Complete DUI Resource in California California DUI attorneys representing clients charged with DWI, drunk driving or driving under the influence
California DUI attorneys representing clients charged with DWI, drunk driving or driving under the influence
Hutton & Wilson, California DUI attorneys representing clients charged with DWI, drunk driving or driving under the influence

Blood Alcohol Concentration (BAC) Calculations

Download EZ-ALC Blood Alcohol Chart Software

Click here to download EZ-ALC When you click on the link above to download EZ-ALC, your web browser will ask you where you want to save EZALCSW.EXE. Put it somewhere you'll remember! After it's done downloading, use the "Run" command to run the file and it will automatically install on your computer, with an icon on the desktop, and another one in "Programs" on your "Start" menu. If you don't want the desktop icon, just click on it once, then right-click and select delete from the pop-up menu.

Fast Eddie's Simple 8/10 Method for Hand Calculating BAC

Click here for an article on how to use Fast Eddie's Simple 8/10 Method (Widmark's formula).

Why Do BAC Calculations From Drink History?

It's possible to use "Widmark's Formula" to calculate a Blood Alcohol Concentration (B.A.C.) based upon known factors about a person, including their weight, gender, and what amount of alcohol they consumed.

It's plain that the defense will want to present expert testimony on this subject to show that the B.A.C. was below the legal limit (Veh. C. §§ 23152(b) and 23155) at the time of driving.

Another Reason For Such Evidence

The defendant has often admitted at the time of arrest, consuming some amount of alcohol prior to driving. Prosecutors often use such statements to impeach the defendant's credibility. They have the prosecution expert testify as to how much alcohol the defendant had in him at the time of his blood, breath or urine test. Then they have their expert state how many "drinks" the test result means the defendant had to have consumed. The answer usually makes the client look like a liar. And the jury is told that they can't trust anything the client said, like, when he said he was not affected by the alcohol. But your expert can often reconcile the chemical test result with your client's admissions. The defendant's credibility is thereby restored, not only with regard to what he drank, but on everything else in his testimony.

Thus, Widmark calculations can be essential not only to showing that the defendant's alcohol level at the time of arrest was below the legal limit, but also to showing that the defendant is not a liar.

There is an excellent discussion of how to use the EZ-ALC software in court in, Fitzgerald, Edward F., Chapter 12 "Use of the EZ-ALC Computer Program by Attorneys and Experts", in {NEED LINK} Intoxication Test Evidence, 2d ed. (Deerfield, IL: Clark-Boardman-Callaghan, 1995).

Whether you or your expert use the hand or computer calculation method it will be necessary for your expert to testify as to the results.

If the calculations have been done by computer your expert can state that he relied upon the statements of EZ-ALC's technical consultant, Randall C. Baselt, Ph.D., for his opinion that EZ-ALC correctly uses Widmark's formula and is scientifically valid. This is no different than an expert testifying that he believes his hand held calculator correctly adds, subtracts, multiplies and divides, based upon the manufacturer's representations that it does that. The program comes with a complete description of how it operates, along with a copy of Dr. Baselt's extensive curriculum vitae, showing him to be a leading authority on the subject.

It is not necessary to show that the computer was functioning properly or that the software was working the way it was supposed to (People v. Lugashi (1988) 205 CA3d 632, 252 CR 434 - Case contains an extensive collection of authorities on the subject). For what may be a contrary view see Snyder, R., Assuring the Competency of Computer Generated Evidence (No. 1, Winter, 1989) 9 Computer/Law J. 103-121.

See also State v. Pressnall 804 P2d 936 (Idaho CtApp 1991) - Blood Alcohol Concentration (B.A.C.) calculations based upon Widmark formula admissible to rebut Breath Alcohol Concentration (Br.A.C.) evidence; Tarantino, J.A., "Using Computer Generated Simulations in Alcohol Related Trials", DWI Journal, 6 No. 8, Aug. 1991 (Fanwood, NJ: Whitaker Newsletters) 1.

We wrote the book on DUI in California

California Drunk Driving Law is recognized by thousands of California attorneys and judges as "The Bible of Drunk Driving Defense"™.

It's unrivaled!

This site brought to you by the authors of California Drunk Driving Law.