What is Chain of Custody?

The Chain of Custody definition refers to the document or paper trail showing the seizure, custody, control, transfer, analysis, and disposition of physical and electronic evidence. Chain of custody labels & forms are also used in most chemical sampling situations to maintain the integrity of the sample by providing documentation of the control, transfer, and analysis of samples. Chain of custody documents are especially important in environmental work where sampling can identify the existence of contamination and can be used to identify the responsible party.

There are several applications that can be considered Chain of Custody, not just the most common medical form. These forms can also be found in the Airline, Military, Forestry, Law Enforcement, and Animal Control industries.

What is a Chain of Custody Form?

Most Chain of Custody documents consist of a multi-part form and label combination with barcoding/numbering. The form contains all the history of a project, and can be a laser, snap out, or continuous format. The label is used for tracking any portion that may be transferred away from the history. The label can be a variety of stocks depending on the application and what the label is to be applied to. The barcoding/numbering traces the two back to each other and is on both the form and the label. There is a variety of symbology that can be used for the barcoding and is usually eight- or 10- digit crash Arabic numbering.

Accuracy is a very important function of a solid Chain of Custody procedure because good form carries reliable and defendable documentation. For example, if you have a drug testing Chain of Custody form for laboratory testing, making sure that the numbers are all the same on each form, and that the label will not fall off the tube is very important. Having a wrong number on the form could cause the test results to be traced back to the wrong person.