A Liverpool-born carpenter has been convicted of murdering two girlfriends and dumping their dismembered remains in canals in Rotterdam and London as police warned he could be responsible for more killings.
John Sweeney, 54, currently serving life for the attempted murder of a third woman, was found guilty at the Old Bailey of killing former US model Melissa Halstead, 33, in Amsterdam in 1990, and Paula Fields, 31, a mother of three, in north London 10 years later.
As he awaited sentence police said they feared at least three other women may have fallen victim to a man described as "hateful, controlling, possessive" and "prone to outburst of rage and murderous violence".
Detective Chief Inspector Howard Groves said they were seeking information about a Brazilian woman called Irani, a Colombian called Maria, and a Derbyshire woman called Sue who was possibly a nurse who moved to Switzerland.
All knew Sweeney in north London and are thought to have disappeared in the 1980s and 90s. The Dutch are also investigating claims made to friends by Sweeney that he had killed two German men known to Halstead.
The case is the first cross-border murder investigation to be funded by the EU's Eurojust scheme.
Sweeney, who worked under assumed names on construction sites in London and mainland Europe, disposed of the bodies of Halstead and Fields "in the most callous and undignified manner possible" and "convinced himself he would never be caught for these heinous crimes", said Groves.
Grieving relatives said it was their wish he die behind bars.
A cold case review by Rotterdam detectives in 2008 finally linked the cases of Halstead's unidentified headless, handless corpse found in an army kitbag in the Westersingel canal in 1990 and Fields, whose remains were found in six holdalls by schoolboy anglers in the Regent's canal, Camden, a decade later.
Halstead, a freelance photographer and beautician in London, had embarked on a tempestuous relationship with Sweeney, a divorced father of two.
A man "disposed to using serious and escalating violence" towards girlfriends, he had threatened his ex-wife with a hammer and axe and he had three convictions for attacking Halstead in London. When she was deported as a visa over-stayer in 1988, he followed her to mainland Europe.
In Vienna he attacked her with a claw hammer, but received a suspended sentence after she pleaded for leniency. "I asked her if she had lost her friggin' mind," Halstead's sister Chance O'Hara, 63, said in video evidence from California. Shortly afterwards, Halstead vanished from her flat in Amsterdam.
She had, with chilling accuracy, predicted her death at Sweeney's hands, telling her sister if she ever went missing he would have killed her. But for 18 years no one linked her disappearance to the body found in Rotterdam.
Dutch detectives were finally able to put her name to the remains in 2008, one year after the first missing person DNA database was set up in the Netherlands.
Sweeney, who said he regularly took cannabis and LSD and described himself in poems as "a manimal – twisted, confused, and very dysfunctional", returned to London in 1990 and embarked on a relationship with nurse Delia Balmer, living in Camden.
When she ended it in 1994, he attacked her, repeatedly hacking at her with an axe and knife, until a male neighbour ran to her rescue and hit him with a baseball bat. Sweeney ran off, and remained on the run for six years.
Balmer, who suffered terrible physical injuries and psychological damage, told police of a bizarre confession he had made shortly before the attack. He spoke of having killed a girlfriend called Melissa, and two German men who were friendly with her. He would make the same confession to his best friend, and later his ex-wife whom he had married at 18 in Skelmersdale, saying he had done things that "would make her hair stand on end", the jury heard.
During six years on the run Sweeney is believed to have worked on building sites in Europe and London under various aliases. One of these was "Scouse Joe", and this was what Fields, a fellow Liverpudlian, knew him as.
A crack cocaine user leading a chaotic life which involved prostitution in London, she vanished in December 2000, three months after meeting him in Highbury, north London.
On finding her remains, police inquiries led to a Scouse Joe whom police then realised was Sweeney.
A search of premises connected to him yielded two sawn-off shotguns, a Luger pistol, a bamboo garrotte and a hoard of more than 300 vividly violent drawings and poems depicting bloody attacks on female victims and police.
One drawing entitled The Scalp Hunter showed a female skull hanging from a belt and an axe. A poem written on the back of a scratchcard read: "Poor old Melissa, chopped her up in bits, food to feed the fish, Am*dam was the pits." Removing correction fluid from a drawing, police revealed a gravestone with "RIP Melissa Halstod bon 12th December 56. Died - ".
Rejection was not in Sweeney's lexicon, the jury heard. Both Halstead and Balmer were attacked as a result. As for Fields, with whom he also had a sexual relationship, the motive may have simply been he believed she stole money and his phone from him for drugs.
When arrested in his cell at Gartree Prison, Leicestershire last April for the two murders, police discovered another drawing, an image of a headless body dissected into 13 pieces in way Fields' had been. As the jury heard, time had failed to dim his fascination and preoccupation with dismemberment.
