Lucky hunch caught serial rapist

A detective has spoken of the lucky hunch which led her to serial rapist and murderer David Mulcahy.

Detective Constable Caroline Murphy was hunting a vicious rapist who was terrifying women in north London in 1998.

She heard about John Duffy while off-duty and discovered he was in Whitemoor Prison but, by chance, he had been talking to a psychologist about his crimes and the involvement of a second man, David Mulcahy.

She decided to investigate further. "It was just a hunch," she said.

Mulcahy, of Chalk Farm, north London, was eliminated from Det Con Murphy's inquiry - but she consulted forensic experts to see if modern science could be used to prove he was the second man in Duffy's crimes.

After tracking down exhibits from years earlier, DC Murphy got the breakthrough which proved her right. A scientist rang to say Mulcahy's DNA had been found linking him to the rape of two Danish au pairs on Hampstead Heath in 1984.

DC Murphy said: "It was the best phone call of my life. They could hear me shouting down the corridor".

She added: "He really thought he was above the law," said the policewoman. "He makes my skin crawl."

The rape victims were traced in their homeland and broke down when DC Murphy told them their attackers had been caught.

Detective Superintendent Andy Murphy praised the DC Murphy's role. He said: "She had the foresight and professionalism to set the wheels in motion".