Physical evidence can play a critical role in all sorts of criminal cases. For instance, weapons with fingerprints can help prosecute someone in an armed robbery, bags of drugs can send someone to jail for trafficking, and clothing can play a vital role in sex crime cases.
Once the police collect this evidence, what do they do with it? What happens between then and the prosecution using it as an exhibit in court?
Finding out could be the key to persuading a judge to declare an item of evidence inadmissible.
If you can prevent the evidence from being admitted in court, you will weaken the prosecution’s case against you. Here are some things to look at if you want to challenge the validity of evidence:
- How did the police collect it? When officers arrive at a crime scene, they need to secure it. Failing to do so with speed increases the chance of evidence contamination.
- Did they transport, categorize and store it correctly? Police stations must maintain records of everything that happens to an item. Let’s say they collected a bag of white powder and tossed it into a drawer with some other bags of white powder collected from a different, unrelated site. Without proper documentation, how can they tell which relates to your case?
- Who had access to the evidence? The more people who access an item, the greater the risk of contamination, confusion or tampering.
If accused of a serious crime, you need to consider all defense options available. The prosecution intends to put you behind bars, and they may be willing to overlook chain of custody errors to do so. You need to ensure you do not allow them to.