If you are facing DWI charges in Texas, you probably know that the prosecution must prove its case beyond a reasonable doubt. A violation of the chain of custody is a defense that should always be explored.
There are specific rules for collecting physical evidence from a crime scene. The evidence must be collected, marked, stored and moved in certain ways.
This is known as the chain of custody. The chain of custody is a record of who had physical possession of the evidence and when. This documentation is meant to show that the evidence has not been altered or tampered with in any way, proving its reliability.
How the prosecution must prove chain of custody
The chain of custody must be proven for all evidence of a crime. Foe example, in a DWI case, the chain of custody applies to evidence such as blood samples. The prosecution must show more than simply the blood test results demonstrating that you were over the legal alcohol consumption limit.
To successfully prove chain of custody, prosecutors need to provide documentation such as data printouts of laboratory tests and records showing compliance with hospital procedures and calibration of testing equipment. They must also provide documentation showing exactly who had the evidence and where it was at all times.
If any of these documents cannot be produced, the prosecutions case becomes weaker. Knowing that the evidence could have been tampered with because of a gap in the chain of custody could plant a seed of reasonable doubt in the mind of a jury.
Know your rights and possible defenses
Proving that the police did not comply with the chain of custody requirements is one potential defense to a DWI charge. If there is evidence the chain of custody was broken, the DWI charge could be dismissed.
A break in the chain of custody is only one possible defense that could help you get a DWI charge dismissed. There are other defenses that may be available to you. It is important to thoroughly explore all possible defense options after a DWI charge.