Genetic photofits - fact or fiction?

We know that our genes have an influence on how we look, from the colour of our hair and skin to our height or the shape of our face. But when it comes to trying to predict what a criminal might look like from a sample of their DNA, what can we be sure about, what’s got potential, and what’s pure speculation? To find out, Kat Arney spoke to Martin Evison, professor of forensic science at Northumbria University.