LONDON -- After Linda Davies reported to police that her 15-year-old daughter had been raped, it took three months -- plus two dozen phone calls and a threat of legal action -- before police questioned the suspect, a 28-year-old neighbor.
"I gave police his name, address, mobile phone number, car registration -- everything but his passport," said Davies, 44, a strong-minded mother of two daughters. "I was basically begging them. He lived five minutes away from us."
The suspect was finally arrested but acquitted at a trial in which the judge told the jury that he was "in a way a man of good character" because his previous criminal convictions, for possession of stolen goods and marijuana, did not involve violence.
Davies was furious at the judge, who also instructed the jurors to ignore the victim's young age, and at police, who lost cellphone records that contradicted the defendant's account.
"This has shattered us," Davies said. "We felt like the whole system was against us."
Davies said she was stunned to learn that her daughter's case was the rule, not the exception. According to government statistics, only 5.7 percent of rapes officially recorded by police in England and Wales end in a conviction.
"What are they saying?" Davies asked. "That 95 percent of women that come forward are telling lies?"
In Britain, a nation whose justice system has been used as a model around the globe, government officials and women's rights activists agree that rape goes largely unpunished.
Solicitor General Vera Baird, who oversees criminal prosecutions in England, estimated that 10 to 20 percent of rapes are brought to authorities' attention. According to government figures, 14,000 cases a year are reported and 19 out of 20 defendants walk free.
"There will never be proper female equality and appropriate dignity afforded to one-half of the population if it's possible to rape somebody and get away with it," said Baird, one of the highest-ranking women in the British government.
Thousands of victims each year once chose not to go to police because of shame, women's advocates say. Now, the advocates say, the bigger reason is that rape victims feel the system is stacked against them.
A 2005 report commissioned by the police found a "culture of skepticism" in the justice system when it came to rape cases, and recommended shifting the focus from seeking reasons not to believe the accuser to gathering evidence to support the charge.
Lisa Longstaff, spokeswoman for the London-based group Women Against Rape, said rape cases are "not a priority" for busy police and prosecutors and, as a result, "so few rapists get locked up that those who do feel unlucky rather than guilty."
Even some cases that do end in a guilty verdict stir outrage. Last year, a judge sentenced a 24-year-old man to two years in prison for having sex with a 10-year-old after concluding that the girl had "dressed provocatively."
Patricia Scotland, England's first female attorney general since the job was created in the 15th century, appealed that sentence. It was increased to four years.
Longstaff and others said that despite advances toward equality, sex crimes run up against a persistent societal bias -- pronounced in the male-dominated police and judicial system -- that women have only themselves to blame.
Julie Bindel, a feminist activist and writer, said there has been a huge cultural shift since the 1950s and 1960s toward acceptance that unmarried women can have casual sex.
But, she said, "women are allowed that bit more freedom as long as men behave. When men choose not to, it comes right back at women: 'What did you do to stop him? What was it about you that he chose you to rape?' "
In a TV ad paid for by the police of Manchester, England, that began airing this month, a young man and woman are enjoying a pleasant evening, at first.
But after they drink alcohol, dance and kiss, the man leads the woman out of the nightclub, yanks her pants down and forces her to have sex against a wall as she cries, "No. No. . . . Get off of me."
In the ad, the man is locked up. In real life, according to dozens of interviews with victims and experts, this is exactly the kind of case that ends in an acquittal, if it goes to court at all.
Acquittals are often won on the "mucky sex" defense -- that the man got mixed signals from the woman and what resulted really wasn't rape.
Danielle West, 30, who reported to police that she was raped after a boozy office Christmas party in December 2006, said police seemed uninterested in her case once she said she had been drinking heavily.
West, an American who manages a team of Web analysts in London, turned visibly upset as she recounted her story in a quiet corner of a coffee shop. She said police, rather than giving her the benefit of the doubt, seemed "hostile" and intent on trying to "trip me up."