What kind of a mother would try to kill her own child?

One like Andrea Yates of Houston. Or, Lashuan Harris of Oakland. And now, police say, Fotini Huntley of Citrus Heights.

Although the circumstances vary, the accused mothers have something significant in common. All are said to suffer from severe mental illness.

Cases like these befuddle the courts and other systems designed to hold criminals accountable and protect innocents. Is a mother who is mentally ill capable of safely caring for a child? And if a tragedy occurs, should the mother be held fully accountable?

These are some of the questions being asked in the aftermath of the attempted drowning of Antonia Huntley. Antonia's mother, Fotini, was arrested Sept. 27 after she told police that she had drowned her daughter. Family members and others told The Bee that Huntley has long suffered delusions and other symptoms of schizophrenia. Officials are looking at her husband Anthony's possible culpability for leaving her alone with Antonia when he went to work.

The 2-year-old girl was taken to UC Davis Medical Center and is fighting for her life. Her mother, who was arraigned Wednesday in the medical ward of the Sacramento County jail, has been charged with attempted murder.

"How could a mother do that? It's something that most people just can't understand," said Karen Henry, president of the California office of the National Alliance of the Mentally Ill. "But what you have to remember is that mental illness is a brain disorder. It affects how people think."

The issue has been explored in several high-profile cases, including that of Andrea Yates of Texas. After two trials, Yates was found not guilty by reason of insanity in 2006 for drowning her five children in the bathtub. In 2005, Lashuan Harris of Oakland was declared insane by the court after she tossed her three small sons to their deaths in the frigid San Francisco Bay.

Lawyers have suggested that Huntley's mental illness will play a role in her defense in Sacramento Superior Court.

"This case is the very definition of mental illness: a mother harming a child. It's so unnatural," said Diane B. Howard, a public defender who represented Huntley at her arraignment. "It's extremely tragic for everyone."

Huntley, 36, is a longtime schizophrenic who in recent months had been taking her medications and functioning well, said her husband, Anthony.

"Something happened and I don't know what," he said in a telephone interview. "I know that if she were in her right mind, she would never hurt our daughter. She loves our daughter."

Others familiar with the case said that the girl has stayed with relatives in the past because of fears about her mother's behavior, and that Child Protective Services has been in contact with the family. Those sources declined to be identified because of the sensitivity of the matter.

CPS deputy director Laura Coulthard would not confirm agency involvement, citing confidentiality laws, but said cases involving mentally ill clients are particularly difficult.

"In general, mentally ill parents pose huge challenges to public agencies because each family's situation is different," she said in a statement. "It is difficult to monitor a parent's compliance with taking medication, and situations change quickly.

"Our role is to assess the child's safety and to put an appropriate safety plan in place. This plan can range from enlisting family members as a safety net to offering voluntary or court ordered CPS services."

Anthony Huntley said that he and Fotini, a native of Greece, have been married for 14 years. Their relationship has been turbulent at times, he said, because of her mental illness.

"But it's not her fault. It's very hard to control the human mind," he said.

Lately, Huntley said, she has been taking injections of Haldol, a powerful anti-psychotic drug, and seemed relatively stable.

Studies show that people with serious mental illnesses are slightly more likely to be violent than others if they are not receiving treatment, said Sacramento psychiatrist Michael Meek. If they're in treatment, he said, they pose no greater risk than the population at large.

Call The Bee's Cynthia Hubert, (916) 321-1082.