British police are to conduct a study of serial killers in an effort to improve detection.
Rosemary West
The research, sparked by the 2002 sniper attacks in the United States that left 10 people dead, will also study so-called "honour" killings, ritual murders and stranger attacks - where the killer is not known to the victim, the Metropolitan Police said.
Convicted serial killers such as Rosemary West and Dennis Nilsen could be interviewed as part of the research.
West, a housewife, was found guilty in 1995 of killing 10 women and girls, whose bodies were found dismembered and buried at her home.
Nilsen was jailed for life in 1983 for six murders after a plumber found human flesh blocking the drains. The civil servant confessed to killing 15 down-and-out young men at his London home over five years.
Where possible, the detectives who were in charge of the original cases will carry out the interviews.
But former police chief Mr Keith Hellawell, who has interviewed "Yorkshire Ripper", Peter Sutcliffe, welcomed the initiative but warned researchers not to believe everything they hear.
"They tell you what they want you to know and to some of them, particularly I found with Sutcliffe, it was a game," he told BBC Radio 4's Todayprogramme.
Sutcliffe was jailed for life in 1981 for murdering 13 women and trying to kill seven more. He claimed he heard voices from God telling him to murder prostitutes.
Other types of murder to be analysed for the research include homophobic slayings, contract killings, the murder of sex workers and killings of elderly people.