OKLAHOMA CITY — The rape convictions that could put a fired Oklahoma City police officer behind bars for life are vindication for some of the women he targeted, and also a reminder of how difficult it is to achieve justice in such cases.

Most victims never report sexual assaults, and those who accused ex-officer Daniel Holtzclaw were even more vulnerable as poor black women, many with checkered histories of crime and addiction.

A grandmother’s bravery in telling her story made all the difference this time. After Holtzclaw pulled her over, forced her to expose herself and perform oral sex, she filed a complaint that triggered a search for other victims.

In this case at least, it changed a narrative all too common in sex crimes: The jury found him guilty of rape.

“I didn’t do anything wrong,” the grandmother said Friday, showing her face on camera and revealing her name as Jannie Ligons. “So all I can say is, I was innocent and he just picked the wrong lady to stop that night.”

Holtzclaw was found guilty of sex crimes against eight women, and acquitted of charges involving five others he encountered on night patrol. Jurors recommended 263 years, including 30-year sentences for each of four first-degree rape convictions.

Holtzclaw trembled and sobbed as his verdict was read Thursday night, on his 29th birthday. His emotional outburst prompted jail authorities to keep him on a 24-hour watch.

Though prosecutors assembled a damning case with GPS pinpoints, records of computer background checks and other evidence, some worried the all-white jury might doubt the testimony of his victims, all of whom are black. Holtzclaw is half-white, half-Japanese.

“It shows that there is a hope for our country, there is hope for society and there is hope for all our sisters, mothers, wives, daughters, who are victims of rape, no matter what race they are, what ethnicity they are, what social-economic class and status they’re in,” said Benjamin Crump, a lawyer who plans to sue the city on behalf of some of the women.

Crump was flanked by Ligons and Shardayreon Hill, who testified that Holtzclaw assaulted her while she was handcuffed to a hospital bed.

The AP does not identify victims of sex crimes without their consent, but these two women spoke publicly and agreed to be identified.

The verdict left the Rev. Al Sharpton “somewhere between jumping and shouting ‘Hallelujah’ and feeling aggrieved for the women.”

Most rapes go unpunished in America, and sex crime convictions are even more unlikely when law enforcement officers are accused, said Kimberly Lonsway, a research director at End Violence Against Women International.

This verdict is “remarkable,” she said. “The odds were completely against it.”

Just one-third of all rapes and sexual assaults were reported to police in 2014, lower than any other category of crime, according to the National Crime Victimization Survey by the Bureau of Justice Statistics. Only 40 percent of these led to an arrest or some other kind of closure, according to an FBI study of rapes reported in 2010.

Even when a victim comes forward and an arrest is made, prosecutors may decide they lack the evidence to win a conviction.

When they do go to trial, a courtroom win is never assured: 68 percent of rape cases adjudicated in the 75 largest U.S. counties in 2009 led to a conviction, according to the federal data. And even when convictions are won in cases where rape was the most serious charge, 11 percent don’t go to prison.

The “he said-she said” nature of such cases make them even more difficult when officers are accused.

The very few who are tried in court can be portrayed as heroes, swaying juries, said Joshua Marquis, the district attorney in Clatsop County, Oregon, who has prosecuted numerous cases against police, including some sexual offenses.

Meanwhile, their alleged victims often “are not sympathetic people” – they may have criminal records or don’t testify convincingly.

“That’s not an accident,” Marquis said. “All kinds of sex offenders, particularly intelligent ones, they pick their victims because they know they’re less likely to be believed.”