They were called to help a drunken woman get out of a taxi in 2008. The woman testified that she passed out and awoke to being raped in her apartment.
Moreno told jurors he lay alongside her in her bed for a while, but they didn't have sex.
Mata was accused of acting as a lookout. He said he was napping in the living room while the others were in the bedroom.
During the trial, prosecutors told a stunning story of police misconduct and a perverse abuse of power. The officers acknowledged a number of missteps - including Moreno making a bogus 911 call - but said they weren't crimes and the rape allegation was a product of the woman's muddled memory.
Mata, 29, and Moreno, 43, have been suspended until a police department review after their trial.
The woman, a fashion product developer who's now 29, had gotten very drunk while out with friends celebrating her impending promotion and move to California. A cab driver called police for help getting her out of his taxi around 1 a.m. on Dec. 7, 2008.
The officers didn't tell dispatchers where they were as they repeatedly returned to her apartment - to check on her at her request, they said. Indeed, Moreno, a police officer for 17 years, admitted he invented an excuse for one of the visits by calling 911 with a phony report of a homeless man sleeping in a nearby building's lobby.
Her blood-alcohol level was three or more times the legal limit for driving, and she acknowledged during days of testimony that her memory of the night was spotty. But she said she acutely remembered the rape, and other vivid snippets - police radio chatter, flashlights, the same man's voice urging her to drink water in her bathroom and later asking her if she wanted him to stay in her bedroom - made her certain that her attacker was an officer.
"I couldn't believe that two officers who had been called to help me had, instead, raped me," said the woman, who has sued the city seeking $57 million over the incident.
After consulting prosecutors, she secretly recorded a conversation with Moreno a few days later. He alternately denied they had sex and seemed to admit it, particularly by saying twice that he'd used a condom when she asked him:
Woman: Did you use a condom?
Moreno: Ma'am --
Woman: I'm sorry but I'm completely freaked out --
Woman: -- about getting pregnant or anything.
Moreno: Ok ma'am, you're not going to get pregnant because nothing happ...yes Ma'am I used a condom. You don't have to worry bout being pregnant. You don't have to worry about getting any diseases. Ok? Alright. Alright.
Moreno told jurors he was just "telling her what she wanted to hear" because she had suggested she'd go into the stationhouse where he worked and make a scene.
No DNA evidence was collected in the case, and experts debated whether an internal mark found during an examination of the woman could be interpreted as a sign of rape.
Moreno said he was only trying to console and counsel the woman about drinking during his series of visits, as he shared his own struggle with alcoholism some years before, killed a cockroach in her bathroom, made plans to have breakfast with her and sang to her a verse of Bon Jovi's "Livin' on a Prayer."
On the last visit, Moreno said, he suddenly found himself fending off drunken advances from the woman.
"I told her, `There's another time for this. Not tonight.' ... I kind of had her by the shoulders, and I said, `We're not doing this,'" he told jurors.
But, he said, he wound up in her bed after she fell and got stuck between her bed and a wall and needed to be freed. He said he stayed there with his arms around her for a time, out of sympathy, but kept his uniform on and didn't have sex with her.
Mata, a police officer for about five years, acknowledged during his testimony that he couldn't be sure what had happened between the two while he was snoozing on the woman's sofa. But he said he didn't believe Moreno had raped the woman because "Ken wouldn't do something like that."
He was charged with rape under state legal principles that hold an alleged accessory as responsible for a crime as the main defendant.