It's looking likely that San Francisco District Attorney George Gascón will file misdemeanor domestic violence charges against newly sworn-in Sheriff Ross Mirkarimi.

Prosecutors are "convinced this is very real," said a source with firsthand knowledge of the investigation.

The case stems from a New Year's Eve incident in which Mirkarimi allegedly grabbed his wife - former Venezuelan telenovela star Eliana Lopez - with enough force to leave a bruise.

Lopez has said publicly that she has no complaint against her husband and that the incident had been taken "out of context."

Mirkarimi's attorney, Robert Waggener, said Tuesday that the sheriff and former District Five supervisor is braced for whatever charges might come.

"We have a complete defense," he said. "I don't think an offense was committed."

Gascón's office, however, believes that a video of a bruise on Lopez's arm and text messages discussing the episode justify the filing of misdemeanor charges, said the source, speaking on condition of anonymity because the D.A. has not authorized anyone to discuss the possible charges publicly.

Police armed with a search warrant obtained the video and text messages from a neighbor of the couple who reported the alleged incident. The messages are said to include comments Lopez made to the neighbor about the incident and the state of her marriage.

Sources tell us that prosecutors don't have enough evidence to justify filing a felony charge, which requires showing that a defendant inflicted an injury that resulted "in a traumatic condition."

A misdemeanor case could be filed before the week is out, we're told.

Gascón has refused to divulge his thinking in the case and said prosecutors would treat it like any other domestic violence investigation.

"We are taking a hard look at this case, and will only file if we make a determination that this case can be proved beyond a reasonable doubt," D.A.'s spokesman Omid Talai said.

For Mirkarimi, any charge involving domestic violence carries huge personal and political risks.

"It's all statutorily spelled out what happens in a domestic violence case," Waggener said. "There is a lot at stake."

Under federal and state law, Mirkarimi would have to forfeit his gun if he is convicted even of misdemeanor domestic violence. The City Charter doesn't require the sheriff to pack heat, but Mirkarimi would have the distinction of being the only sheriff in the state barred from being armed. (The restriction helps explain why domestic violence convictions are almost always a career killer for other law enforcement officers.)

A misdemeanor conviction would also result in a requirement that Mirkarimi attend domestic violence counseling classes every week for a year.

If Mirkarimi is charged and fights the case in court, his and his wife's private lives would go on full public display. If Lopez doesn't cooperate, she could be subpoenaed to take the stand.

Because laws have been made tougher, defendants in misdemeanor domestic violence cases in California no longer are eligible for pretrial diversion - a maneuver that allows some defendants accused of other crimes to have their charges dismissed after they undergo counseling or meet other court-imposed conditions.

While emphasizing he doesn't think any charges should be filed, Waggener said there were several reasons why prosecutors would be limited to pursuing a misdemeanor conviction against Mirkarimi instead of a felony.

They include that Lopez isn't the one who went to police, that the investigation is centered on "a single bruise of unknown cause," and that Lopez has "made it very clear that she and her son are safe and that she has a great relationship with her husband."

"There is no way that situation gives rise to a felony," Waggener said, "and I do not think any offense was committed at all."

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