When collecting a sample, what additional step is necessary?

When collecting a sample, it is essential to collect a control sample to ensure the accuracy and reliability of the results. A control sample serves as a baseline or reference that can be used to compare against the evidence sample. This is particularly important in forensic investigations to determine if the results obtained from the evidence sample are valid and not influenced by external factors or contamination.

Control samples help confirm that the testing process is functioning as intended. They allow investigators to identify any inconsistencies or anomalies in the results. For example, if a substance is being analyzed, having a control sample of the same material that has not been subjected to the conditions of the investigation can help verify whether the results obtained from the evidence reflect true findings or are affected by contamination or errors in the analytical process.

The act of notifying law enforcement, storing samples for later review, and discarding unwanted samples each hold importance in the process, but they do not provide the same level of validation for the analytical results that control samples do. Control samples are integral to the scientific process and enhance the credibility of the investigation's conclusions.