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Per Se BAC Limits and DWI Cases

Raleigh DWI LawyerShea Denning has a hypothetical DWI jury instructions question at the UNC School of Government’s Criminal Law blog. She asks whether, in a per se DWI case, the judge should give the pattern jury instruction which includes the line: “The results of a chemical analysis are deemed sufficient evidence to prove a person’s alcohol concentration.”

Or, instead, she asks whether the jury should be told that the .08 or higher BAC should be treated like any other piece of evidence – that there is no presumption that is created by a .08 or above, and that the evidence ban be believed wholly, in part, or not at all.

As I wrote last week, the truncation of the Intox EC/IR II results in a DWI case in North Carolina creates at least one evidentiary problem in that it masks the potential margin of error produced by the breathalyzer machine.

Juries, therefore, are not given complete information about the two potential blows in a DWI case – and the difference can be as much as .029 between the two blows, with North Carolina statute and administrative code establishing that such a result would be admissible in court.

Moreover, juries are given very little information in a typical DWI trial about how the machine works, how it was calibrated, whether its internal diagnostics are affected by ambient air or external electronic interference.

In State v. Narron and State v. Simmons, the Court of Appeals in North Carolina essentially agreed in as much as current statute permits the results from the chemical analysis to be used as proof that the person had a BAC above a .08 at a relevant time after the driving, but does not require the jury to find that the burden has been met.

In other words, whether the BAC result exceeds the .08 at a relevant time after the driving, that result is entirely up to the jury to decide. The jury is not merely a cog in what I’ve heard Raleigh DWI lawyer John Fanney call “push button justice.” The jury gets to make up its own mind.

So in answer to Shea Denning’s question, the proper instruction, whether demanded by the state’s appellate courts or not, should at least add the provision that a .08 or above on a chemical analysis does not require the jury to find the person guilty, and can be believed or disbelieved by the jury along with all other evidence presented at trial.



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