You often hear about the drug testing process that evidence goes through when a person is accused of committing a drug crime. The evidence is stored for a while before being tested at an official drug lab. You also often hear about blood testing that occurs when a drunk driving suspect has his or her blood drawn. Again, it is stored and tested to determine if the blood contains any alcohol or other intoxicants.
Think of all the things that can go wrong during the storing or testing phases of this evidence. Someone with access could steal the evidence. Someone may tamper with the evidence, either knowingly or unknowingly. The person who actually performs the test may botch the procedure, leading to an incorrect result. Numerous outside factors could affect the substance being tested, and any of these aforementioned instances would be a violation of a person's criminal rights and an affront to due process.
That's why when drug testing centers or police facilities are found to have improperly stored or tested such substances, the story is a big deal. Last month, an investigation was launched into the storage and testing process in the state of Delaware.
The state's Office of the Chief Medical Examiner has been sealed by Delaware police as they conduct an investigation into the incident. Apparently evidence was tampered with, substituted or disappeared. Many cases may have been affected, and it could result in the dismissal of some of them. However, that won't be known until the extent of the evidence breach is discovered.
Source: CNN, "Drug tampering inquiry could mean justice delayed in Delaware," Mary Kay Mallonee, Feb. 24, 2014