Collecting evidence at a crime scene or from a person, analyzing in the laboratory and ultimately presenting results in the courtroom show how forensic science plays a vital role in the criminal justice system.1 Quality plays a fundamental behind-the-scenes role in various industries worldwide, but if you have ever considered the role of quality in the forensic crime lab industry — it is pivotal, since the level of quality in handling and analyzing crime scene evidence can have enormous ramifications for the legal system.
When an item of evidence, essential in securing a conviction appears in court, forensic investigators have to ensure the integrity of the chain of evidence. Therefore, laboratories should make the concept of quality control (QC) central to everything they do with the evidence, from the crime scene to the courtroom. Failing to present competent evidence can result in the guilty going unpunished or an innocent person being convicted.2
Gamble? Not with your sample
During laboratory investigations, QC covers the need to store samples correctly, run control and reference samples when doing DNA analysis and record every imaging from a microscopic examination of the sample. Whatever the nature of the evidence, it is prone to degradation, contamination or inhibition. Trace evidence, in particular, is vulnerable in this respect.
What is your laboratory doing to ensure one can count on the results presented for a sample? Does your current system fully account for the quality differences in your forensic sample? Or, have you found the most suitable method for assessing the quality of your forensic sample?
To address these quality requirements and challenges, we have identified and helped laboratories implement a system that can yield robust results for a wide range of challenging samples and is more suitable to overcome problems inherent of such samples, enabling the identification of complete genetic profiles. A unique and innovative “Quality Sensor” system has been integrated into our Investigator STR PCR kits, providing a more comprehensive quality assessment of your sample, and a better assessment of total amplifiable DNA. The Quality Sensor (QS), containing resultant alleles “Q” and “S”, allows differentiation between robust amplification, degradation, inhibition, lack of amplification of DNA and failed PCR amplification.3
In a recent study, researchers from Sam Houston State University and the University of Queensland have shown that the QS system is highly sensitive and reproducible in confidently screening poor quality samples and avoiding needless processing of such samples. The QS system can, therefore, improve any laboratory workflow by assisting forensic experts in the selection of the most appropriate rework strategy — which samples to amplify, the relevant DNA target to amplify, whether to concentrate or dilute a sample prior to amplification, based on the additional information given by the sensor, resulting in improved success rates with challenging samples.
Watch an on-demand webinar to learn how the same laboratory has used a streamlined workflow that combines quantitative and qualitative assessment of difficult samples while helping them make the most informed decisions for successful outcomes.
For forensic scientists, such reliable results motivate them to help solve crimes and see justice done. For crime investigation, it means enhancing the court’s confidence in the evidence being presented.
Confident in your findings? Download our latest infographic to find a recap of the challenges and benefits of successful QC in forensic science.
- 1. https://www.nij.gov/topics/forensics/pages/welcome.aspx
- 2. https://www.encyclopedia.com/science/encyclopedias-almanacs-transcripts-and-maps/quality-control-forensic-evidence
- 3. Zgonjanin, D., Soler, M.P., Antov, M., et al. (2017) Validation and implementation of the Investigator 24plex QS Kit for forensic casework. Forensic Science International: Genetics Supplement Series Vol. 6: e77-e79 https://www.sciencedirect.com/science/article/pii/S1875176817302184