SAN JOSE — Prosecutors plan to retry a former San Jose police officer on charges that he raped a woman while on duty in 2013, even though a jury at the end of his first trial deadlocked 9-3 last week in favor of acquitting him, this newspaper has learned.

In the meantime, former officer Geoffrey Graves, 40, was freed late Wednesday on $100,000 bail and placed on supervised release, including GPS monitoring via an ankle bracelet. Graves, who was fired about six months ago, had been held for nearly a year in jail without bail.

Prosecutors decided to retry Graves partly because some of the nine jurors who voted to acquit him had been open to discussing the case further and might have changed their minds, sources familiar with the case said. But two female jurors were dead set on finding him not guilty, prompting the panel to report to the judge that they were hopelessly deadlocked after deliberating for less than two days, the foreman said in a brief interview with this newspaper.

“The jury was a lot closer than it sounds,” said the foreman, adding that he voted guilty and is pleased there will be a retrial. “There were many jurors going back and forth.”

District Attorney Jeff Rosen released a terse written statement that mentioned the jury but did not fully illuminate his reasons for going forward.

“After a careful and comprehensive review of the case, the trial, the jurors’ perspectives, and other factors, we are moving forward to retry the case against Mr. Graves,” the statement said.

Deputy District Attorney Carlos Vega, who headed the initial prosecution, will re-try Graves for rape, which carries a maximum sentence of eight years in prison, and for unlawful entry with intent to commit rape, an enhancement that carries a life sentence. The new trial could begin as soon as this summer.

Alternate Public Defender Kristin Carter, who put on a vigorous defense that many courtroom observers credited with causing the mistrial, is expected to represent Graves again.

“We’ll be prepared and are confident that we’ll prevail,” Carter said. “He’s not guilty of any crime as three-quarters of the jury found, and I expect the same result if not better the next time.”

During the trial, Carter eviscerated the credibility of the alleged victim, an approach that worked with many members of the panel, according to another juror who voted in favor of convicting Graves. But the juror said he was more impressed by the fact that Graves’ fellow officers broke the “code of silence” and testified against him. The fact that the woman reported the crime only after being stopped for a DUI three weeks later and couldn’t remember much about the incident didn’t bother him.

“There are women who don’t report being raped until years later,” the juror said, “or never report it.”

In March, Graves had offered to plead no contest to one count of rape to avoid being convicted of enhancements that could have landed him in prison for life. But the District Attorney’s Office refused the offer, gambling on a conviction.

Graves, who was fired in September, was among a team of four cops who responded to a disturbance call in the middle of the night on Sept. 22, 2013, at an apartment where a woman was in a drunken argument with her husband.

No crime occurred, but the woman asked to be taken to the Marriott TownePlace Suites hotel, where she had worked as a maid. Graves and another officer escorted her there. Three weeks later, she reported to police that Graves came to the room and raped her, saying she was initially afraid to report it because she was in the country illegally, and also was afraid her husband would reject her and police would retaliate.

Vega, a former Torrance police officer himself, argued that Graves “took advantage” of a “perfect victim” — an illegal immigrant who was drunk and spoke little English — and “raped one of the most vulnerable people in our society.”

Graves first denied, during interviews with investigators, that he had sex with the woman, but testified during his trial that he lied repeatedly until after he learned that her DNA was found on his bulletproof vest because he was afraid of being fired. Graves also told jurors that he could tell during the three minutes he was alone with the woman while he drove her to the hotel that she wanted a tryst with him: “I remember thinking, she really liked me and was totally coming on to me.”

The third juror who voted against Graves didn’t believe the ex-officer.

“An illegal woman with five kids who had been drinking and in a family fight was totally hitting on him?” said the woman who voted to convict Graves. “It made no sense.”

Contact Tracey Kaplan at 408-278-3482. Follow her at Twitter.com/tkaplanreport.