SAN DIEGO -- A former supervising investigator in the county Public Defender's Office was sentenced Monday to three years probation and 200 hours of volunteer work for taking her son's girlfriend to Acapulco so the younger woman could avoid testifying about an alleged beating.

Karen Cabrera, 59, pleaded guilty Jan. 12 to felony conspiracy to obstruct justice.

Defense attorney Stephen Cline told Judge Kathleen Lewis that his client "went too far and made some bad choices out of love for her son, and nothing more."

Cline, in asking that his client's conviction be reduced to a misdemeanor, argued that Cabrera's case was treated differently by the District Attorney's Office because of the job she held.

Leaving the felony in place would prevent Cabrera from visiting her son in prison, Cline told the judge.

Public Defender Henry Coker, speaking on behalf of Cabrera, said he worked closely with the defendant for 10 years, describing her as a hard- working investigator who worked long hours on behalf of abused children who had become wards of the court.

"She has paid a huge price in as much as she has been publicly humiliated," Coker said.

Cabrera retired from the Public Defender's Office after her arrest last April. She now works at a furniture store, Cline said.

Deputy District Attorney Laura Gunn told the judge that prosecutors did view Cabrera's case more seriously because the defendant had the specific purpose of trying to undermine the government's case against her son.

Gunn urged the judge not to reduce the charge because doing so would send a message that the criminal conduct was "minor" and allow others to think it was OK to make witnesses "vanish" and make them unavailable at trial.

"What this defendant did strikes at the heart of the criminal justice system," the prosecutor said. "A crime against the justice system needs to be treated seriously."

But the judge, who agreed to reduce the crime to a misdemeanor, noted the defendant had no prior record and a lot of community support.

"The crime itself, I think was an aberration," Lewis said.

The judge said there was "no doubt" that Cabrera would be successful on probation.

At a preliminary hearing last November, Cline said Cabrera acted "foolishly" when she helped Jennifer Wren by purchasing airline tickets to Acapulco and escorting Wren to the Mexican resort in September 2008.

At the time, there was a $100,000 warrant out for Wren's arrest for failing to show up to testify in her boyfriend's domestic violence trial.

Cabrera's son, Alejandro "Alex" Cabrera, pleaded guilty one month later to assaulting Wren in May 2008 and was sentenced to seven years in prison, Cline said.

Outside court, Cline said Cabrera was one of the "most cherished" investigators in the Public Defender's Office.

"It's been hell for her," Cline told reporters. "She loves her son to no end. It's cost her dearly."

The attorney said Wren had made it clear "from the beginning" that she didn't want anything to do with the case against her boyfriend. Cline said Wren's mother wasn't prosecuted even though she was sending money to her daughter while the younger woman was in Mexico.