'Tis the season to give

If you're planning on drinking and driving over the holidays, you might seriously think twice. More and more counties will be conducing No Refusal weekends over the holidays.

The popularity of the initiative is no surprise given that most no-test drunk driving trials are a coin flip proposition. Add in a number on a piece of paper and, suddenly, the success rate for the prosecution soars. That number can be scary.

The attraction for law enforcement and prosecutors is that blood evidence is a powerful tool in front of juries. Armed with blood evidence of intoxication, prosecutors can win convictions in more than 90 percent of drunk-driving cases, said Houston police Capt. Carl Driskell, who works in the traffic enforcement division. 

And often, lawyers say, defendants faced with blood evidence admit their guilt and don't bother with a trial. "If it bleeds, it pleads," said Fort Worth prosecutor Richard Alpert.

But, it's only a number.

Blood tests are conducted by unbiased scientists wearing white lab coats. They're performed by employees of law enforcement agencies. The very people who are trying to convict your client are the ones performing the tests.

Just think about that for a second. Think about that before you walk your client up to the bench to plead out the case. You don't accept the officer's opinion that your client was intoxicated. You don't accept the premise that the coordination exercises he performed at the scene are conclusive proof of anything. But you will accept a number on a piece of paper signed by a lab technician in the employ of the crime lab or the DPS as proof positive that your client is up a creek without a paddle.

You realize they didn't even test the blood itself?

What? You didn't know that? Remember all that talk about Henry's Law with the alcohol jar attached to the back of the breath test machine? Remember that machine supposedly measured the amount of alcohol vapor in your client's breath? It was an approximation of an indirect measurement.

Guess what. That's all a blood test is. After they mix a bunch of chemicals and salt into the blood sample, the lab tech takes out a sample of... air. That's what's being sent through that fancy gas chromatograph. Not blood - air. It's as much an indirect measurement as a breath test.

Prosecutors around the state push for No Refusal weekends because they know that most defense attorneys will crumble when they see the number. Put the state to its burden. Force the prosecutor to explain to a jury how the machine works. It's only a number.