I spend last week at a continuing legal education conference in Ft .Collins , Colorado. The conference was the brainchild of Wisconsin DUI lawyer Andrew Mishlove and sponsored by the National College of DUI Defense. The conference had two components . First , it taught some basic science skills on blood alcohol testing. Secondly , it taught trial skills on how to communicate the science during trial. During the training , I had the opportunity to visit the Rocky Mountain laboratory . The Rocky Mountain Laboratory is a working forensic laboratory in Ft. Collins. I thought I would share my observations from my visit.
The tour was broken down into five stages with instructors at each stage to explain what was going into each critical step in analyzing a blood alcohol sample.
- Receiving the Blood Alcohol Sample.
The first step in the forensic toxicology lab is to properly document the sample when it arrives at the lab. A blood alcohol sample can be dropped off at the lab or mailed into the lab. The receiving clerk takes in the sample. The clerk must create a paper trail to maintain the chain of custody, assign the blood sample a unique lab number and takes steps to make sure the sample belongs to the right person. At the Rocky Mountain Lab , the receiving clerk makes a visual inspection of the sample to make sure the seal was properly in place and to ascertain if the blood had clotted.
The next step is the blood must be pi petted into a vial for testing. A pipette is simply a tool to measure exact portions of a blood sample to be placed into a vial. Only a portion of the blood sample is used for testing.
- Preparing the Sample
Once the sample is pi petted, it is ready to be prepared. You are probably asking yourself why does it need to be prepared ? All blood alcohol samples usually have propane added to the vial as a n internal standard. Also, a salt solution is added.The sample was placed into ma numbered slot to make ascertain the lab tested the right sample.
- Running the Sample.
After the sample is prepared , it is ready to be tested using a head space gas chromatography with flame ionization detection. The machine will test numerous samples. The first step is to place all the samples , controls , calibrators , and blanks onto a tray or carousel. The samples are then tested by the gas chromatography. The samples are reported using a computer software program. The machine does all the testing.
The gas chromatography machines don't run forever without some maintenance .Before the sample is vaporized by the flame ionization, the sample is run though capillary columns. The capillary columns need to be clipped and replaced on a periodic basis.
This is just a brief overview of my day at the Rocky Mountain Laboratory allowing some folks to visit the lab. For some reason , the Tennessee Bureau of Investigation does want to give me a tour. I would highly recommend this course for all DUI defense lawyers