'Killer may have drugged prostitutes'

London: Their corpses were naked, dotted by jewellry and unmarked by signs of struggle or trauma - raising questions of whether a suspected serial killer may have drugged five young prostitutes before stealing their lives in the provincial English town of Ipswich.

The last body found by a roadside was identified on Friday as one of five young victims who got hooked on drugs and took to the streets. It was perhaps their addictions that lowered the women's guard and dulled their resistance.

Forensic psychologists have asked whether the killer lured and then anesthetised the women with drugs - deaths that were seemingly less violent than those of the Yorkshire Ripper who beat and sodomised many of his 13 victims in the 1970s. None of the Ipswich women showed signs of significant trauma or sexual assault.

''It may be this person gets a real charge out of playing God but doesn't necessarily relish hearing the screams of his victims,'' said a psychology professor at Northeastern University in Boston, James Alan Fox.

Fox has authored several books on serial killers.

''Drugging them would have also made it easier on him - psychologically - to abduct them, kill them and dispose of their bodies,'' he added.

One woman died from asphyxiation. Another died from what a coroner called a 'compression to the neck'. The causes of death for the other three were still unknown and it would take some more days to complete toxicology reports.

Experts from Britain's equivalent of the FBI - the National Centre for Policing Excellence - were in Ipswich, a rural town about 70 miles (110 kilometers) northeast of London. About 300 specialists have been recruited for outside help.

The fifth victim was identified on Friday as Annette Nicholls, 29.

Police said they have linked the five cases. The bodies were discovered in a 10-day span just kilometers apart from each other.

The conditions of two bodies found in water have hampered forensic efforts.

Paula Clennell, 24, who told reporters days before her death that she was afraid but needed to return to the streets to support her heroin habit, was formally identified by police on Thursday.

Gemma Adams, 25, was the first woman to be found in a stream on December 2. She grew up in the Ipswich area and became hooked onto heroin after leaving a job at an insurance company. Her boyfriend reported her missing November 15.

''The fact that they were drug users will make the work more complicated,'' Suffolk Police spokeswoman Sandra Graffham said.

Professor Kevin Dominic Browne, who specializes in forensic psychology and whose center in Birmingham has studied serial killers, said the killer may have used drugs on his victims to ensure he had power over them.

He said often these types of killers have been abused themselves or suffered some type of trauma associated with sexual intimacy.

Serial killers usually enjoy the physical sensation of killing, preferring strangulation or bludgeoning to guns and other weapons, experts say.

"It's a myth, however, that they are always sociopaths who lack remorse or compassion," Fox said.

''It may be that this guy wants to control or posses his victims more than he wants to cause him pain. Drugging them is also a cleaner kill,'' he added.

The naked body of 24-year-old Anneli Alderton was spotted in the woods December 10, after initially being mistaken for a discarded mannequin. Police said it appeared that Alderton, who is the mother of one, had been strangled.

The body of Tania Nicol, 19, was found in a pond after being reported missing November 1.

Police said an anonymous donation of some 10,000 pounds had been given so prostitutes could stay off the streets until the killer was caught.