Karen's body was found on farmland near Glasgow in April after she went missing following a night out at the city's Sanctuary club.
A 21 year old man – Alexander Pacteau – has been charged with the Cork woman's murder.
Officers want to speak to a woman wearing a short pink dress – but stress she's in no way linked to the 24-year-old's death.
Jillian Whelan – Deputy Editor with Global Scotland – says police believe the woman may have crucial information that could help.
