Officers have released a photo of an 'extremely dangerous' man with links to neighbouring Hemel Hempstead areas as part of an investigation into a case of abduction and rape.
The Metropolitan Police first issued an appeal on Sunday April 28 to identify a man wanted in connection with the abduction and rape of two women.
And Hertfordshire Constabulary said he was also linked to the rape of a 21-year-old in Watford on April 21.
The force believes the man is 34-year-old Joseph McCann who has links to Aylesbury, as well as Watford and Ipswich.
A £20,000 reward has been offered by the Metropolitan Police for information about his whereabouts that leads to his arrest and prosecution.
During the attack in Watford, the victim was approached by a man holding a knife in Hagden Lane at about 3.30am.
She was forced into a blue Ford Mondeo and driven around the town for six hours before being raped.
The Hertfordshire force said the suspect had been identified after the attack was reported to them on April 22.
Another woman was abducted from a street in Chingford at 12.30am on Thursday April 25.
And a third woman was taken from a street in Edgware 12 hours later, at 12.15pm.
The women were driven to a hotel in Watford and an attempt was made to book a room around 1pm.
When this was unavailable, the suspect left the premises.
Around 2.30pm, a struggle between the women and the suspect took place on Osborne Road in Watford and the women managed to escape.
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Officers are still trying to trace a silver or grey-coloured Ford S-Max people carrier, which had false registration plates, in connection with the offences.
Detective Chief Inspector Katherine Goodwin, from the Met’s homicide and major crime command said:“We would ask anyone with any information about McCann's whereabouts to contact us immediately – McCann is considered extremely dangerous and a risk to the public and we ask people not to approach him, but instead call 999.
"If you wish to remain anonymous, call Crimestoppers - it is vitally important we trace him in connection with these offences.
“My team continues to work around the clock and we are making progress in furthering the investigation."
The women, both in their twenties have been left traumatised by the incident and are receiving support from specialist officers.
Officers are treating the incidents as random but linked attacks.
A 33-year-old man arrested on Sunday April 28 on suspicion of conspiracy to rape has been released under investigation.
McCann is known to use false names, most recently Joel.
He is described as being of muscular build and 5ft 10ins tall.
McCann has blue eyes, a bald head or shaved blonde hair with a light-coloured short beard.
He has a slight Irish accent and is described as having a distinctive tattoo of the name ‘bobbie’ on his tummy.
Officers believe McCann may attempt to disguise his appearance.
Anyone who can help is asked to call the incident room on 020 8785 8244 or 999 quoting CAD 3041/25Apr.
Alternatively tweet @MetCC and or Crimestoppers anonymously via 0800 555 111.