A 25-year-old Vancouver man was reportedly arrested last month on suspicion of DUI after a crash on Highway 14. According to the Washington State Patrol, the man had been headed eastbound when his vehicle moved into the right land and collided with another vehicle driven by a 19-year-old Vancouver man, forcing his vehicle to the right.

After overcorrecting, the latter driver crossed both lanes to the left and struck the barrier. Both vehicles ended up crossing the lanes and stopping on the right side of the highway. Neither driver was hurt, nor was the 17-year-old passenger of the driver who was struck. Both vehicles were, however, totaled.

Sources didn't provide any details as to what led police to believe the 25-year-old man had been under the influence of alcohol at the time of the crash. As soon as police suspect a DUI may have occurred, though, they immediately begin collecting any evidence they believe would support an arrest.

Among the evidence will be signs of erratic driving, breath alcohol odor and other personal signs of intoxication, field sobriety tests and preliminary breath tests, incriminating statements, and blood-alcohol tests.

Police receive extensive training to be able to detect certain types of evidence, and it may happen that officers are so used to seeing them that they may assume they are there when they actually are not. Certain types of evidence, like the field sobriety and preliminary breath tests, are unreliable and may be subject to error. Positive breath tests have been disputed based on defects or inaccuracies in the device.

There are a variety of ways that evidence collected by police can be inaccurate and subject to legitimate criticism. It is the task of a defense attorney to ensure that inaccurate or poor evidence, or illegally obtained evidence, does not form the basis of a conviction.

Source: Oregonlive.com, "Man hurt in Vancouver crash charged with DUI," Sally Ho, April 15, 2012.