Britain's worst serial killer couple, Fred and Rose West. Fred West was charged with 12 murders, but killed himself in prison before he could face trial. Rose West was convicted of 10 murders, including that of her own daughter.

Britain's worst serial killers haunt a city, decades after their grisly crimes

Updated 0533 GMT (1333 HKT) June 4, 2021

London (CNN)Police excavations at a cafe in the quiet English city of Gloucester revived a half-century-old puzzle: What happened to Mary Bastholm, a carefree 15-year-old girl who went missing in 1968.

The teenager has long been feared to be among the victims murdered by Fred West, but her body has never been found.
West and his wife Rosemary, who met the following year, would go on to become Britain's worst serial killer couple.
A week-long dig, at the Clean Plate cafe in the heart of the historic city, resulted in the discovery of "no human remains or items of significance" according to police; but the search has stirred up painful memories.
An officer is seen outside the Clean Plate cafe on Southgate Street on May 11 in Gloucester, as police search for remains of the missing girl Mary Bastholm.
More than 25 years have passed since the UK was shocked by the grim discovery of multiple sets of human remains in what had appeared to be a nondescript family home in Gloucester. But too many questions remain unanswered for the public's fascination with the case to end, or for the city to rest easy.
Fred West was charged with 12 counts of murder, though there have long been suspicions that other young women and girls were abducted, tortured, sexually abused and killed by the Wests. Fred killed himself age 53 before he could stand trial, taking many secrets to his grave.
Rosemary, known as Rose, was convicted on 10 counts of murder in November 1995; she will remain in prison until she dies. She has always protested her innocence and has revealed nothing about the case over the years.
Adding to the horror is that those killed include family members: Charmaine West, Fred's 8-year-old stepdaughter from his first marriage to Catherine "Rena" Costello, and Heather West, 16, his eldest child with Rosemary.
It was Heather's death in 1987 -- believed to be the final murder carried out by the pair -- that was to lead police to uncovering the mutilated remains of victi