SAN DIEGO -- A supervising investigator in the county Public Defender's Office was charged with conspiracy and witness-tampering, for allegedly hiding her son's girlfriend in Mexico after he assaulted the younger woman, an arrest warrant revealed Monday.

Karen Cabrera, 58, was arrested Friday by investigators from the District Attorney's Office and released on $50,000 bail.

According to the arrest warrant, Cabrera's son and Jenifer Wren, his girlfriend of 10 years, were involved in a domestic violence incident last May 29.

Alejandro "Alex" Cabrera burned Wren with a hair iron, punched her in the nose and kicked her in the head and stomach, causing her to spend four days in a hospital, the court document alleges.

He was subsequently charged with two felony counts and allegations that he caused great bodily injury to Wren.

Last Aug. 5, Wren failed to show up for Cabrera's preliminary hearing and a judge issued a $100,000 bench warrant for her arrest, according to the court document.

Investigators, with the help of Wren's father, figured out that she was in Acapulco.

Further investigation revealed that last Sept. 7, Wren and Karen Cabrera flew to Acapulco together, and that the older woman returned to San Diego alone a week later, the arrest warrant states.

Receipts indicated Karen Cabrera paid for the airline tickets, according to the document.

Last Oct. 28, her son pleaded guilty to the charges against him.

A week later, Wren appeared in San Diego Superior Court to surrender on her outstanding arrest warrant.

Deputy Communications Director Steve Walker said the district attorney's office would not comment on the case against Karen Cabrera until she is arraigned, which is scheduled for April 13.