If you stand accused of a crime then the police and prosecution will search for evidence to back up their case. Some of that may take the form of physical items – such as an item of clothing found near a crime scene or a bag of drugs allegedly found in your garage.
To defeat the charges you face it can help to try and disprove the validity of the evidence. In the case of physical evidence, one way to do this is to examine the chain of custody.
What happened to the item from the moment the police collected it?
Let’s say the prosecution wants to present the bag of drugs in court. Provided it is actually drugs, rather than talcum powder or some other innocuous substance, and provided the police legally took it, your best option might be to introduce doubt as to its validity.
Maybe the police did collect something from your garage, but how can they prove the item the prosecution intends to present in court is the same item? How can they prove that no one swapped out the bag they found which actually was talcum powder and replaced it with one full of cocaine?
The police should record every movement of the items they collect as evidence. They should record who had access to it and when. Asking for these custody records and looking for gaps – breaks in the chain of custody – gives you an opportunity to cast doubt on the validity of an item. If a court agrees that the chain of custody was broken then hopefully they will declare the evidence inadmissible.
Learning more about this and other defense methods is crucial if the police have accused you of a crime.