Former Army captain Brian Witty subjected four women to terrifying assaults over a 16-year period, each time being arrested after his victims reported the crime.

But it was not until after the final attack, in which he raped a 42-year-old woman who he met through a dating website, that he was finally charged.

Lisa Longstaff, of pressure group Women Against Rape, said: "The trial has shown, once again, that with serial rapists police and CPS have a serial response - they believe the rapist rather than his victim, turning their backs on women's pain."

Witty, 41, now a City financier, faces an indefinite jail term after being convicted of three counts of rape and one sexual assault at London's Kingston Crown Court.

Police fear the "predatory rapist" may have attacked other women and have urged them to come forward.

• Army officer accused of rape said alleged victim had 'eaten chicken suggestively'

  12 Apr 2012

• Former para accused of rape 'told victim he was a good looking bloke'

  11 Apr 2012

The court heard that when Witty's first victim, a nanny he met in a pub in Fulham, tried to fight him off, he told her: "I don't believe this, I'm a good looking bloke."

The first attack took place in 1995 at his flat in Kensington.

A second victim, a 25-year-old recruitment consultant who Witty had contacted through datingdirect.com in May 2006, met him for drinks in Covent Garden.

At the end of the evening he offered to walk her to a taxi rank but instead dragged her into an alleyway where he sexually assaulted her and told her she was "lucky".

A woman who Witty met at a City pub in October 2008 where he claimed she was "suggestively" eating a chicken skewer, became his third victim when he raped her at his riverside flat.

He was finally charged after raping his fourth victim, who he had again met through datingdirect.com, in August last year.

Detectives then traced and re-interviewed his three previous victims, who agreed to attend court to give evidence.

Witty maintained his innocence and maintained each of the women "must have a screw loose" but was convicted following a five-week trial.

Prosecutor Edmund Gritt said each of them described how Witty could be "charming, likeable, attractive, understanding, nice" but could become "volatile".

Their accounts showed how once he had been drinking, he would become a man who was "determined to get what he wants and who will not take no for an answer".

Mr Gritt told jurors: "Time and again, the CPS made a decision not to charge Brian Witty.

"In that context, the importance of the decision not to charge in the first three cases, they confirmed in Brian Witty's mind he was untouchable and could carry on how he wanted."

Detective Inspector Michael Murfin, of the Met's Sapphire sex crime unit, said: "We want victims to have the confidence that we are here for them, will believe them and will conduct our investigations professionally.

"Brian Witty is a predatory rapist and I would urge anyone who thinks they may have been raped or sexually assaulted by him to contact the police in complete confidence."

Witty, a father-of-two, who is originally from Hull but now lives in Teddington, was remanded in custody to be sentenced on May 25.