Mother and son, who conceived a child, are accused of violating probation

There are always more of these.

An Antioch woman and her adult son whose incestuous relationship resulted in a child are accused of violating terms of their probation for convictions of child endangerment last year. Lawyers were back before Contra Costa Superior Court Judge Laurel Lindenbaum yesterday to discuss the latest allegations.

The unusual case was reopened after the county Social Services Department reported receiving a taped phone message in December in which the 45-year-old woman and her son, 24, were discussing custody options for their 3-year-old daughter, conceived through the illegal relationship. Officials believe the defendants were together while the call was made to the county department.

"Somebody heard the message and was convinced it was the guy's voice in the background," said prosecutor Paul Sequiera. The Chronicle has not identified the defendants in order to protect the privacy of the girl and five other minor children belonging to the woman. All of the children have been placed in foster care.

Authorities believe mother and son began the incestuous relationship several years ago when he moved back into the family home after having been raised by other relatives for much of his life. Police were alerted in October 1999 when one of the woman's daughters told a teacher about the relationship.

Although incest charges are rarely filed in California, prosecutors decided they had to act because the illegal relationship produced a child. But when authorities learned last year that the child was not suffering from any long-term genetic disability, the defendants were allowed to plead no contest to child endangerment charges. As part of the plea, they were sentenced to two years in state prison. That term was suspended by Lindenbaum, who agreed to place the defendants on five years probation with an order that they stay away from each other.

Yesterday, Lindenbaum said she would defer making any ruling about the alleged probation violation until June after a custody case involving the defendants' daughter is concluded. Lawyers said the judge was unlikely to send either defendant to prison for violating a stay-away order unless the conduct had caused harm to the girl.

"Basically, Judge Lindenbaum's attitude is that these people better not do anything that negatively impacts the kid," said defense attorney Stuart Willis, who represents the son. "But if they want to be in the same room in order to schedule visitation over the phone, I don't think anyone has a problem with that." Willis said his client has not been living with his mother. Both defendants sat in different rows of the courtroom audience and did not look at one another while waiting for their case to be called, lawyers said.

Contra Costa Deputy Public Defender Paul Mariano said county officials dislike his client and were eager to report her to the probation department for any violation, however minor. "They were morally offended by the nature of the offense," Mariano said. "But Judge Lindenbaum treated it appropriately."