Friday's Daily News had a terrific story by William Bender about a female Philadelphia police officer whose sexy photos on Facebook and MySpace made Bender's piece a cover story.

More interesting to me is the fact that the officer, Deona Carter, is the subject of a federal lawsuit accusing her and two fellow officers of beating a bartender in University City in 2008.

Neither Carter nor the city would comment, but the suit charges that the attack on the bartender, Geovanni Tanner was unprovoked, and that the cops then fabricated a story that he'd attacked them. Ten witnesses signed statements supporting the Tanner's account for the lawsuit.

The bartender was of course arrested and charged with assaulting the officers, and all three testified under oath at a preliminary hearing that he'd attacked them. But here's the part that bothers me: After the District Attorney's office talked to other witnesses and dropped the charges, no disciplinary action was taken against the officers.

That reminded me of a story I did for the Daily News in 2009 about a police officer named Alberto Lopez who was caught on a convenience store security camera roughing up a woman who'd had a fender-bender accident with his son.

The woman, Agnes Lawless, was charged with assaulting the officer based on his account, and she spent the night in jail. Lopez repeated his story under oath at a preliminary hearing, and Lawless was held for trial. But once the store video became public, the case against her evaporated.

After my story was published Lopez got a suspension. Lawless sued, and the city settled the case.

But a really troubling part of the story is that the convenience store clerk told investigators that three times after the incident, police officers came by and spoke with him about the security tape, and two asked if he would erase it.

Nothing happened to any of those officers who sought to destroy evidence to protect Lopez. If they'd been successful, it's all but certain Lawless would have been convicted of assaulting an officer.

And that's the moral of this story: If you don't hold officers accountable when they lie or try to cover up misconduct, they'll feel free to back each other, even when they know one of them has done something wrong.

"The District Attorney and Police Commissioner are always attacking people in the community who don’t come foreward (with information about crimes)," said Lawless' attorney, Alan Yatvin. "But it’s the same thing in law enforcment. It's the police version of 'no snitchin.'"

"You have to attack this wall of silence," Yatvin said. "The problem with police misconduct is that if there’s a code of silence, police officers will think they can get away with things, and you’ll never stop this."