Procedure Of Blood Draw In Fort Worth DWI Cases

The blood test, to be helpful to the jury, should be done as soon as possible after the time of driving. However, it’s frequently an hour or two, or more, before that blood test is taken. That might be because it takes that long for the officer to get to the person to a proper testing facility to draw the blood. Maybe it took that long for the officer to go through the procedure of arresting the person, warning the person of their rights, and getting a warrant to allow the drawing of the blood. That’s the first problem. But then, the next procedure is that it should be done in a proper medical facility.

However, often officers will do blood testing in a facility that is not suitable or not clean enough, maybe even in a jail or in other unsuitable places, which can cause problems with the blood test result. The next procedure would be for a properly trained medical professional, usually a registered nurse, to do the blood draw. Sometimes the law allows it to be a person with less training than a doctor or a nurse to draw blood, a person who is called a phlebotomist who has a very small amount of training will be allowed to do the blood draw. In some places in Texas, police officers will actually go through a very small amount of training and be declared competent to draw blood from people, but I would say that they are actually not competent and they don’t get enough training. They don’t get enough practice to do it properly, yet the law sometimes allows that to happen.

Process of Drawing Blood in Fort Worth

A proper, medically trained person should prepare for the blood test. They have to use a properly prepared blood test kit with a grey top tube. The grey top just designates what kind of tube this is, and if it’s proper for forensic blood testing. That’s very important because the tube must contain two different substances in it; one is an anti-coagulant so that once the blood is drawn, it doesn’t coagulate and make it unusable. The second is a preservative, which is supposed to keep the blood from fermenting and creating its own alcohol. This is a problem with blood testing. They must have a proper kit, and it should be a kit that’s not expired. That test tube is prepared so that it has a vacuum so that it does not have anything else in it and nothing else can get into it to contaminate it prior to it being used for a blood test.

The blood testing person with proper medical training should properly prepare the blood draw site. They should draw from a vein in their arm, and they should prepare the blood draw site by cleaning it with the correct antiseptic, not with anything that contains alcohol. Sometimes they use an antiseptic that contains alcohol, which could contaminate the blood draw. Whatever antiseptic they use, they should start in the middle, where the blood is going to be drawn from, and then move outward in concentric circles to clean that location.

They should move from the center out in concentric circles, because this way any contaminants, such as dirt or germs that the antiseptic picks up, are being moved away from the blood draw site. What happens many times is the blood draw a person, without proper training or not using proper procedure likely just move the cotton or with the antiseptic on it back and forth across the blood draw site. That’s improper because all that does is it just moves the germs, dirt, and bacteria back and forth across the site where the blood draw’s going to be done. This contaminates the blood draw. Then they need to properly insert a clean needle to draw the blood and draw enough to fill two tubes so that it can properly mix with the anti-coagulant and the preservative so that it’ll be a proper blood sample that can be tested at a later time.

But sometimes they do what we call a short draw which doesn’t get sufficient blood to make it a proper sample for later testing. Sometimes they don’t properly insert the needle, which can damage the vacuum and allow contaminants to get into the blood tube, which then can cause fermentation of the blood sample. Then when it gets tested, all of a sudden they find alcohol from where there wasn’t any alcohol before, because it’s fermented. We understand how that can happen when you get some substance and you add sugar to it. This can happen to a blood sample.

After they draw the blood into the tubes, then they should properly mix the blood with the two substances in the tube. There is a very specific method by which they are supposed to do that, called an inversion. So they should invert the tube at least 5 times both ways 180 degrees to properly mix the blood with the preservative. Now, a lot of times the technician doesn’t do this, or isn’t properly trained and what they’ll do is they’ll shake the tube. This is a problem because then it can cause some of these blood cells in the sample to break or to be damaged. This causes a problem with that blood sample being properly preserved so that an accurate test can be done at a later time.

Mistakes in Fort Worth Blood Tests

Of course, there needs to be proper labeling of these blood vials, and then there needs to be proper caretaking with those tubes after the blood is drawn. They need to be cared for and properly stored in a refrigerated environment. But what we often find is that the blood sample is given back to this arresting officer, who will then put it back in his patrol car in the trunk. Then it’s out there in the Texas heat for a couple of days. The temperature inside the car gets much higher than the temperature outside the car, and this can cause problems with proper preservation of the blood. It can cause the blood sample to be contaminated, or for alcohol to actually ferment in that container. These are all frequent problems with blood testing.

This doesn’t even include the problems that can happen when the blood finally gets to the lab where it’s going to be tested. What they do for the blood test, using gas chromatographs, is they run maybe 50 or 100 samples at a time of different people. They have to properly load these samples into a tray, which goes into this machine, but one little mistake in the way they load it can then mix up the readings for different people. For example, the Joe Smith may actually be the reading for Andrea Stone, and Andrea Stone had 0.18, whereas Joe Smith only had 0.02. Now, Joe Smith’s result is 0.18 just because a little mistake in the way they load the samples in this machine. So there are all kinds of problems that can happen in the blood testing and we can show this.



(682) 204-4066 We cannot receive pictures via text so please send those via email or hand deliver to our office.

(682) 204-4066 No podemos recibir imágenes por mensaje de texto, así que envíelas por correo electrónico o entréguelas personalmente en nuestra oficina.


<!–(682) 204-4066 We cannot receive pictures via text so please send those via email or hand deliver to our office.–>

Copy link
Powered by Social Snap