In any criminal investigation, tamper evident bags are used to collect evidence. In the UK, these bags have to meet specific government regulations in order to be admissible as evidence in court. In line with this, the UK government has published a good practice guide detailing how to use tamper evident bags (TEBs) correctly.
TEBs are made of transparent plastic, are leak-proof and have a strong adhesive seal. As with any piece of evidence that may be forensically examined, the investigator must wear appropriate gloves to avoid accidental contamination.
There are also a number of other points to bare in mind:
- Use the bags in a clean environment and on a clean surface.
- Do not turn the bag inside out or blow into the bag.
- Do not put arms or hands into the bag.
- Place items at an angle so they are clearly visible inside the bag.
How to Seal a TEB
The seal is an orange strip along the top of the bag which is covered with a ‘tear off’ strip. The investigator must ensure that the contents of the bag do not touch the strip. To seal the bag:
- Place the bag on a flat surface.
- Hold one corner of the orange strip with one hand.
- Pull the corner of the touching blue strip with the other hand.
- Smooth down the orange strip.
- Keep contact with the adhesive strip to a minimum.
Opening a Sealed TEB
The bag will need to be opened in order to examine the contents. This should be done by making an incision in the bottom of the bag being careful not to damage the evidence.
Resealing a TEB
The evidence must be sealed in a new TEB with the original TEB added to the contents. It is important that the old TEB is kept in order to prove integrity and continuity of evidence. All details of who is in control of the evidence must be made on the front of the TEB.
You can find further information on this subject by reading the official Home Office guidelines on TEBs here.