There are different physical and chemical tests that police used to determine if a driver is drunk. Physical tests consist of field sobriety tests (FST). These are tests consisting of a battery of criteria if the driver does not indicate that the driver deteriorates. However, only a few of these tests are approved by the National Administration of Highway Safety Administration (NHTSA), the remaining trials have not been subject to peer review or scientific evidence to determine whether they are accurate.

Law enforcement often do not tell drivers that STFC tests are optional, there is no legal requirement to carry out free of charge. Moreover, in Maryland, if you are driving a vehicle, you implicitly consent to a chemical test to determine if you are driving under the influence (DUI) (Section 23612 of the Vehicle Code.). These tests may include a blood test, breath or urine.

Now officials are obliged to inform their choice of a blood or breathe test. However, the Maryland courts have determined that the lack of technical assistance is a violation of the law, but will not result in the test of exclusion of evidence. Analyses of urine occurs rarely more. They are very unreliable and only show a past history of alcohol or drugs.

If you take a urine test and shows alcohol or drugs, the level of alcohol or drugs might have been of use that occurred days or a week before the test. Blood tests are usually the most reliable chemical tests that show the direct level of alcohol in his blood system. However, blood tests are subject to inaccuracy and so blood can be retested to determine a variety of factors affecting the accuracy of the test.


How a DUI defense attorney attack the field sobriety tests?

It is important to recognize that field sobriety tests (STFC) are very unreliable. In fact, in most cases the official testifying that manages the STFC will have absolutely no idea what these tests.

Walk round

To walk test and back, the controller has nine steps, heel to toe, straight. The driver becomes a line and walks in the opposite direction. The official seeks seven tracks that a driver is under the influence:

  • The controller
  • Cannot keep your balance during the instructions
  • Starts the test before the official end stops instructions
  • Makes no to walk from heel to toe
  • Cannot keep up their arms to their sides
  • Loses balance during rotation.

Support leg

This requires the driver to stand on one foot and count to say put your foot down. The test takes 30 seconds. During this time, the official looking four-track that a driver is under the influence: (1) using arms to balance (2) rolling (3) jump for balance (4) touching the ground with his foot putting foot to down. The NHTSA says that 65 percent of people who show two or more tracks during the test will have a BAC of 0.10 higher.


If the blood sample is contaminated can cause an inaccurate result. For example, if the drawer is not properly sanitize the area where the blood is drawn, it could cause contamination. Blood samples should also be stored in different flasks. These special bottles must have just the right amount of preservative to ensure that the blood sample does not ferment. If the bottle does not have the correct amount of preservative really ferment sample and blood alcohol concentration will rise. This will give a result that is artificially high.

If the bottle does not have the proper amount of anticoagulant and the result may depend. Not quickly refrigerate the sample may also be a source of an inaccurate result. In some cases, simply cannot be your blood! Remember that during a normal week of most laboratories handle hundreds of samples various driving under the influence cases. In your case DUI / DWI, we can have your sample analyzed again to see if it matches the blood type. If it is treated as another type of blood, can you imagine if this creates weakness DUI district attorney?


Urine tests are generally used by law enforcement, when a driver is suspected of driving under the influence of drugs. This can be prescription or non-prescription drug, including medical or illegal drugs without prescriptions. Generally, urine tests, where a blood test is available for a particular reason, or because the officer is too far from a medical facility or no one around who is licensed to draw blood are used.

In addition, you can use urine tests when a person has a medical condition such as hemophilia and a Breathalyzer is not available. In addition, if a breath or blood test, a urine test may result in that circumstance well. An earlier law requires the patrol, sheriff or police to give the driver the option of a blood, breath or urine. Urine tests are considered the least reliable form of chemical tests.

The test shall collect only the “metabolites” left in the system of a person of alcohol or drugs consumed previously. This shows a history of use, but does not indicate what the current level of alcohol or drugs in the system of a person when the test was performed. In fact, the Bureau of Forensic Services, the scientific arm of the Maryland Department of Justice (DOJ), said that the amounts of drugs found in the urine sample of a person are almost worthless.