A former Oklahoma City police officer has been convicted of sexually assaulting women he preyed upon in a low-income neighborhood he patrolled.

A jury convicted Daniel Holtzclaw of four charges of first-degree rape and 14 other counts. He sobbed while hearing the verdicts Thursday on his 29th birthday. He could spend the rest of his life in prison, based on the jury’s recommendation he serve 263 years.

The mother of his youngest accuser, who was 17, said the case should demonstrate the problem of sexual misconduct by officers isn’t limited to one police department.

“It’s a problem for the nation,” the mother told The Associated Press.

Holtzclaw was charged with 36 counts for incidents from December 2013 to June 2014, and he was fired in January 2015. He was convicted of 18 counts connected to eight women, all of whom were black and who testified against him.

Holtzclaw’s case was among those examined in an Associated Press investigation of sexual misconduct by law enforcement, a subject that police chiefs have grappled with for years. The yearlong probe revealed about 1,000 officers had lost their licenses for sex crimes or other sexual misconduct a six-year period.

But the number of cases might be higher. Not every state has a process for banning problem officers and those that do have great variations in whether officers are prosecuted.

The victims tend to be juveniles, drug addicts and women in custody.

Holtzclaw’s case began with a report from a grandmother who said he forced her to perform oral sex during a traffic stop. Police found another dozen women who said he assaulted them.

The 17-year-old victim was the last to testify at trial. She recalled him pulling up next to her in his patrol car as she walked home in June 2014. He raped her on her front porch after telling her he had to search her.

Her DNA was found on Holtzclaw’s pants. His lawyer, Scott Adams, argued that DNA could not definitely be established as coming from vaginal fluid.

“I’m really getting upset by the way you’re coming after me,” the girl told Adams at one point during her testimony.

Her mother said she was relieved about the conclusion of a “long journey to justice.”

“I feel like justice has been served today,” she said.

The AP didn’t identify the mother, so as not to name the daughter as a victim of a sex crime.

Several of Holtzclaw’s accusers had been arrested or convicted of crimes, so Adams questioned their credibility. The strategy worked in some cases and not in others.

One woman testified while wearing orange scrubs and handcuffs because she had been jailed hours earlier. Holtzclaw gave her a ride home, followed her into her bedroom and raped her, she said.

“This is better than county jail,” the woman said he told her. He was convicted of forcible oral sodomy in her case.

Adams declined to comment after the verdict was read. An appeal is expected.

“I didn’t do it!” Holtzclaw shouted as he left the courtroom in handcuffs, according to the The Oklahoman.

Holtzclaw was a former college football star who attempted a career in the NFL before turning to law enforcement. He was fired before the trial started.

Oklahoma County District Attorney David Prater said after the verdict that Holtzclaw’s attorneys were responsible for eliminating black jurors from the case and ensuring the case was heard by an all-white jury. Holtzclaw is half-white, half-Japanese.

Prater said the case showed that local authorities will pursue investigations no matter the race or background of the victims.

“I don’t care what they look like, where they go to church, what god they worship, or how much money they make,” he said. “We stand up for people in this community.”