The usual argument is that the underlying procedures for forensic DNA testing were developed in laboratories where pure and known samples were used and retesting always was an option.

• 通常的争论焦点是法医DNA鉴定的基础程序是在实验室中完成的，而实验室中采用的是纯净的和已知的样本，再次鉴定始终是一项选择权。