Originally Posted by Osem

It's only remotely likely if the story that the Police are framing the McCann's is true (which I don't believe). However, they'd have access to items just like that as evidence and judging by the volume of the poor girl's hair from pictures I'd say there'd be plenty in her hairbrush unless her parents cleaned it every day. I think it's safe to assume that the definition of 'substantial' in forensic terms is probably quite different from that which would apply in normal circumstances.