Question

If DNA from an evidence sample and DNA from a suspect or victim share a profile that has a low frequency in the population, this suggests that the two DNA samples came from the same person; the lower the frequency, the stronger the evidence. But the possibility remains that the match is only apparent—that an error has occurred and the true profile of one of the sources differs from that reported by the laboratory. Please discuss the ways that laboratory errors, particularly errors that might falsely incriminate a suspect, can arise, how their occurrence might be minimized, and how to take into account the fact that the error rate can never be reduced to zero.

Please discuss the quality assurance and control.

Answer 1

Laboratory errors can be occurred at any stage of the analysis and diagnostics as there are always chances of human errors of mixing the samples or losing the samples during handling. So there are chances that instead of two different samples the test of same sample was performed resulting into the similar profile instead of two different profiles. So to prevent such errors there should be check at every stage from the sample collection to the processing to the final report formation. The quality assurance is a must thing need to be completed with precision.

For this I would recommend to divide the forensic samples into two or more parts at the earliest practicable stage. While the rest of the parts should be retained at lab for the other test to confirm the results of one with the another and give a verified and correct result to the forensic team. Secondly there should be a provision of performing tests in duplicates for the proper verification of the results. The used and saved portions should be stored and handled separately.