The tests that are given after a driver has been pulled over are to determine if that driver is intoxicated. These tests are only taught to the police once. Officers are trained when they start out in the department and use the same skills and knowledge they acquired in their first few weeks. This skill and knowledge, however, is lost and gets sloppy over the years. Think of the police officer who has been working for 20 years and only had one training course on the balance and coordination tests. Veteran police officers start making the tests their own and likely do not follow the procedures they learned years ago. So, it is clear that the tests administered are not as reliable as they could be. This is a ripe place for attack when figuring out a defense. The reliability of the balance and coordination tests can be challenged by your attorney in other ways as well.
To be able to use these tests as evidence of intoxication they have to be “scientific enough.” So, at the outset of the case, your attorney can challenge the reliability and scientific nature of the tests being used as evidence.