The paradigm shift in DNA profile interpretation

DNA mixtures occur when two or more individuals contribute to a sample. Mixtures can vary greatly in complexity. Key variables are the number of donors, the template amount of each donor’s DNA, and the level of DNA degradation of each donor. There is little published material that we can find about behaviours relating to the limits of DNA mixture interpretation in the 90s and 00s. From our own personal knowledge, we recall that two-person mixtures were regularly examined in the 90s and that a ratio of 10:1 was considered a reasonable limit beyond which the profile was considered too complex to interpret. Three-person and higher order mixtures were seldom attempted.