Yeates Murder: Missing Sock Could Hold Clue

http://news.sky.com/skynews Police hunting the killer of Jo Yeates in Bristol are appealing for help to find what could be a vital piece of evidence. They have revealed that one of her socks was missing when her body was disovered on Christrmas Day. Officers say they're keeping an open mind as to whether it was taken by the murderer as a trophy or might have been used to strangle her. Sky's Martin Brunt has been looking at the case in more detail.