Elisa Frank 's sister and best friend were murdered by Ahmad Otak . Otak stabbed Kimberley , 18 , 15 times and spat on her body . He forced her to lure Samantha Sykes , 17 , and then murdered her . Sam 's mother Julie Warren-Sykes speaks for first time since it happened . Shares her experience in TV show Britain 's Darkest Taboos .
Elisa Frank 's sister and best friend were murdered by Ahmad Otak . Otak stabbed Kimberley , 17 , 15 times and spat on her body . He forced her to lure Samantha Sykes , 18 , and then murdered her . Sam 's mother Julie Warren-Sykes speaks for first time since it happened . Shares her experience in TV show Britain 's Darkest Taboos .