Sharon Henderson's tears are part fury, part despair, and part relief after paedophile David Boyd was convicted of her daughter's murder over 30 years ago. Nikki Allan was brutally stabbed and beaten before her body was dumped in an abandoned building. Boyd, who lived three doors down from the Allans, had previously been convicted of indecently assaulting a child. Despite Sharon's pleas over the years, Boyd had never been investigated until a cold case team used DNA technology to trace him. Boyd will be sentenced next week. Sharon hopes he will be locked away for good.