A part of the crime scene investigation (CSI) involves gathering evidence. The evidence is a crucial part of identifying why and how a crime occurred. Ensuring the evidence is gathered in an accurate and timely manner helps the investigators identify what exactly happened at the scene and aids in the investigation being completed. Without having the proper materials to package the items of evidence would result in poor quality tests. Therefore, properly packaging evidence is the next most important step of the investigation process, behind identifying what happened at the scene. Every state may have their own way of handling evidence and some might be better than others, but they are all trying to achieve the same goal.

When a crime scene is approached, the evidence collected must be maintained and preserved in the same condition it was found to not skew any results. The goals of the CSI are to reconstruct the crime, to preserve the evidence and to collect the evidence in a way that will stand in court. There is a wide variety of evidence that can be considered valuable for investigation such as biological evidence, latent print evidence, foot ware and track evidence, trace evidence, drug evidence, and gun evidence.

Figure 1: Evidence Bag

In evidence packaging, the size of the package and the material it is made of is important and different for each case. If you use a big bag to collect gun powder it could disperse in the bag and be difficult to collect and test once it is back in the lab. Another example is using a bag that is too small for a larger piece of evidence, which could cause the bag to not hold up and eventually break. For basic evidence collection, an assortment of new paper and plastic bags should be used. If old paper or plastic bags are used it can tamper with the evidence. If someone put an old jacket in a grocery bag and some hair was found, the investigator would not know if the hair came from the jacket or bag.

Plastic is used for things that do not need to breathe like metal, while paper is used for items that are wet or need to breathe. Some items can be too wet to store immediately and need to dry some before being placed in a bag. Otherwise the evidence can leak through the paper bag and become ruined. Some items will require a smaller bag and to then be placed in a larger bag for transporting. This smaller bag is called a bindle, which would be used when glass needs to be collected.

Labeling the evidence bag properly is the most important step in continuing the investigation process. The ideal label for an evidence bag would be a sticker that can close the bag and seal it shut. The person’s name needs to be applied to the sticker with instructions written on it for the next person to follow. A way for the sticker to open the bag easily but not be closed the same way will be evident if it was tampered with during transportation. In addition to a sticker being used for sealing purposes, there are other sealing methods used in securing evidence such as heat sealing and lock sealing. Neither of which are as common as the tape sealing method.

Figure 2: Properly Sealed Evidence 

Electronic items require their own bag made from a special material. This bag is called a Faraday bag. The material can block the signal and protect it from static electricity. Cell phones and laptops can be controlled remotely which would allow someone to clear any written evidence that is saved on the phone. The phone needs to be turned off and the battery needs to be removed when it is collected. This is to avoid the phone from reconnecting to another cell tower accidentally and losing information. These bags can also store computer components to block signals. Antistatic material includes paper and cardboard. Items stored in plastic can cause a charge of static electricity and allow buildup of condensation.

Figure 3: Faraday Bag

When the crime scene involves drugs, there are special bags that need to be used when collecting them. These bags are called Kapak pouches, which must be heat sealed for the best closure method. They protect personnel against unnecessary exposure and they are airtight. Kapak pouches are also not a good choice for fresh plant material. After the drugs are sealed in the pouches, they are placed in a paper envelop and then relabeled.

Figure 4: A Kapak Pouch

References

Guard, Case. “Packaging and Labeling Evidence.” Packaging Evidence | Labeling Evidence, 27 July 2015, caseguard.com/evidence-blog/packaging-and-labeling-evidence.

NFSTC. “Crime Scene Investigation.” Crime Scene Investigation: How It's Done, 2013, www.forensicsciencesimplified.org/csi/how.html.

Spear, Terry. “Evidence Packaging: A How to Guide.” Oag.ca.gov, 2013,
oag.ca.gov/sites/all/files/agweb/pdfs/cci/reference/evidence_collection.pdf.

Warrington, Dick. “Properly Packaging Evidence.” Forensic Magazine, 14 June 2016,
www.forensicmag.com/article/2013/02/properly-packaging-evidence#disqus_thread.