Typically, criminal law and civil law work independent of each other. However, especially when it comes to rules of evidence, there is a lot of crossover. One area in particular where this can be seen is drunk driving. In a personal injury lawsuit against a drunk driver, as in a criminal prosecution against such an individual, proving impairment can be key to victory. In both types of cases, establishing the chain of custody with regard to tests and test results is important. Failing to properly do so could lead to a flawed case and a losing position.
What is the chain of custody? Generally speaking, the chain of custody is the line of care and possession of evidence from its initial seizure to its presentation in the court room. In the case of a blood test for toxicology purposes, this means having the initial blood sample collector and subsequent possessors testifying as to their procedures for collecting, keeping, and passing along the sample.
In most cases, it is not necessary to perfectly establish the chain of custody. However, it should be established strongly enough so that the judge and jury can be reasonably assured that the sample passed through the chain in an undisturbed condition and is the same blood sample taken from the defendant. A defense attorney will try to attack the chain of custody, and if a plaintiff doesn't know how to respond to certain evidentiary objections, then the evidence may be ruled inadmissible. If the blood sample cannot be used in court the plaintiff may be unable to prove the key element of intoxication.
Those seeking compensation for damages suffered in an accident caused by a drunk driver need to know the rules of evidence and how to use them to their advantage. A skilled attorney may prove beneficial here.
Source: FindLaw, "How to Suppress Evidence," accessed on Sept. 11, 2016