Lisa Diaz had to save her "precious babies" from an evil world. She drowned them.

A man shrieks at the top of his lungs: "Please 911 PLEASE I need an ambulance!"

Clutching a cell phone and pacing through his house, the man roars with primal anger and pain. "Please help me--hurry--I'm right down the street from the fire station...My wife, I don't know what the fuck she did to my daughters...they are dead...hurry, hurry, please hurry, HURRY!"

After working all day, Plano executive Angel Diaz arrived home on September 25, 2003, at about 6:35 p.m. The garage door got stuck halfway up, so he crawled under it and saw his wife, Lisa, at the door into their house. She looked strange. "Something happened to the girls," Lisa whispered. "I didn't want them to suffer."

Confused, Angel walked through the house looking for Briana, 6, and Kamryn, 3. He found their bodies on the bed in the master bedroom--naked, wet, covered with a blanket--and raced for the phone.

The voice of the male dispatcher breaks through Diaz's screams: "Sir, are they conscious?"

"No, they're unconscious. There's shit coming out of their mouths. I don't know what the fuck my wife did...get your ass over here...please hurry...Oh, GAAAAAWWWWD, PLEASE!"

Pacing through the house into the garage, Diaz turns his fury on Lisa, who'd climbed into her Durango and was sitting in it with the door open.

"Oh, God, you should have seen a fucking psychiatrist!" he yells. "You deserve to die! You fucking stupid idiot!"

As the dispatcher tries to talk him through performing CPR on the children, Angel's voice turns pleading, begging over and over, "Please mama, please mama, please wake up, please, please...don't go baby, don't go baby, please..."

Angel Diaz screams and begs, furious at his wife as well as the paramedics, who take seven long minutes to arrive. The last thing heard on the tape is Angel screaming at Lisa: "What did you do to them? What did you do to them?"

That would soon be clear to the paramedics. The two little girls had been drowned. Their mother was bleeding from self-inflicted stab wounds to her chest, neck and arms. She had tried to pierce her heart.

Arrested and charged with capital murder, Lisa Diaz, 33, joined a string of moms in high-profile Texas cases who'd been accused of the brutal murders of their children.

Only four months earlier, 39-year-old Deanna Laney of Tyler had been arrested for killing two sons and maiming a third by bashing their heads with rocks.

In 2001, Houston's Andrea Yates, 37, drowned her five children in a bathtub.

And in November, Dena Schlosser, 35, also of Plano, became the latest killer mom. She admitted cutting off her infant daughter's arms at the shoulder.

No responsible authority is calling this a trend; mothers aren't necessarily killing their children with any more frequency than they did a decade ago. But the Diaz, Yates and Laney cases could change the way the insanity defense is applied in Texas. Yates, like Laney and Diaz, pleaded not guilty by reason of insanity, a rarely used and controversial plea. The insanity defense is a gamble: Jurors often view the mental health profession with suspicion, fearing killers will fake mental illness to avoid prison or execution. Killers like Kenneth Pierott, 27, of Beaumont, give support to those fears: Acquitted by reason of insanity for the 1996 beating death of his sister, Pierott was charged last April with the murder of a 6-year-old boy found dead in an oven.

Though Yates had a long history of schizophrenia and postpartum psychosis, a jury convicted her of murdering three of her children and sentenced her to life in prison. They relied in part on testimony from renowned forensic psychiatrist Park Dietz, who testified for the prosecution that Yates was not legally insane at the time she killed her kids.

The Yates case prompted a new look at the Texas insanity statute, which holds that defendants are not guilty if they didn't "know" their actions were "wrong." The state, however, doesn't define those words. Efforts to clarify those terms have been proposed to the state Legislature by a loose coalition of legal experts and mental health advocates.

This month, the debate got a boost from the 1st Court of Appeals in Houston, which overturned Yates' conviction. The court ruled that Dietz gave false testimony about an episode of the TV show Law & Order in which a woman drowned her kids and escaped punishment by pleading insanity. The problem: No such episode existed. Dietz's error, the court held, could have implied to the jury that the show influenced Yates.

The case of Lisa Ann Diaz offers a rare and intimate glimpse into the mind of a psychotic killer mom. Unlike Yates, Diaz was acquitted, deemed not guilty by reason of insanity. Even though she hadn't received treatment before the slayings, six experts agreed that she was in a delusional psychotic state when she killed. She believed that people in the neighborhood were watching her, that evil spirits were in her house and that voices were telling her that she and her daughters were going to die a slow and painful death.

If Yates is granted a new trial, jurors will be faced with much the same testimony about her mental state, this time without Dietz. But they won't see what jurors did in the Diaz case: 12 hours of videotapes taken of Lisa in the weeks following her arrest, before anti-psychotic medication stabilized her condition.

Though police made a videotape of the Yates crime scene--including the five dead children--they never recorded Yates. If they had, the jurors would have seen a pathetic, disoriented woman. Would the jury have rendered a different verdict if it had seen Yates in the state she was in just hours or days after she'd drowned her kids?

In contrast to the Yates case, jurors at the Lisa Diaz trial saw directly inside her harrowing world, where germs and worms and evil spirits tormented Diaz and her children. The morning of the slayings, the signs and omens had become clear: So Diaz did what any good mother would do. She set out to save her precious babies.

Wearing dark jail coveralls, Lisa Diaz perches uneasily on a chair, her long black hair parted on the side and hanging past her shoulders. Behind her is a white cinder-block wall of the Collin County Detention Center. The camera frame captures her face and upper body and remains fixed at the same distance throughout eight videos. Her male interrogator is unseen.

A pretty, waif-like Latina with a wide, full mouth, a strong nose and brown eyes behind wire-rimmed glasses, Lisa listens with suspicion as Dallas psychologist Dr. Jaye Crowder explains that he is there at the request of her court-appointed attorney, Steve Miller. It has been three weeks since Lisa's arrest, and Miller wants to have his client examined as soon after the events as possible. Lisa agrees to the interview in a soft voice.

She seems subdued, unexpressive but lucid. Over 12 hours of interviews, Lisa will eventually describe why and how she killed her children. Her voice will fade to a whisper, as if she's afraid guards will overhear. By tape eight, when Dr. Crowder presses her for details about the killings, Lisa stares at the floor, rocks back and forth, licks and bites her lips and obsessively rubs one shoulder. She pauses and mumbles and stares, then breaks down in wrenching sobs.

Dr. Crowder's interview began simply enough: Describe how you grew up.

Born in 1970 and abandoned soon after by her mother, Lisa and her sister Michelle were raised by their great-grandmother until Lisa was 4. After the great-grandmother's death, the girls lived with their great-aunt, where they felt rejected. Their mother, Rosemary Cano, remarried and came to get them when Lisa was 9.

Her mother seemed "like a stranger," and the girls had trouble adjusting to her ways. Lisa had no contact with her father until a visit when she was a teenager. Lisa's stepfather, whom Lisa liked, left after four or five years.

Lisa admits that her mother probably should have left them with the great-aunt. As bad as her great-aunt's home was, Cano's household was worse. "You look a little tearful again," Dr. Crowder says. "Do you remember crying about it?"

"Yeah, at the beginning," Lisa says, taking off her glasses to wipe away tears.

Lisa's childhood unhappiness gave way to a troubled teenage life. Never a disciplinary problem, Lisa made good grades in school until ninth grade, when she got pregnant and dropped out. She later earned a GED. Her first husband, David Sanchez, was controlling and jealous, she says. Lisa gave birth at age 17 to their daughter, Misty. A year later, in 1988, she had another child, whom she gave up for adoption. She married Sanchez when she was 19. The couple had many problems: Sanchez was ordered to attend anger management classes, and Lisa was prescribed Prozac for panic attacks. After several separations, they divorced in 1996.

Angel Diaz, whom Lisa met in Dallas at her job, was a godsend. Stable, well-educated, kind, he worked in quality control management. "He was just like the type of person that I had imagined for myself," Lisa says. They married in 1997, two days before Briana was born; Kamryn followed in 2000. After Briana's birth, Lisa became a stay-at-home mom. Though Lisa admits that she sometimes yelled at her children, she says she couldn't bring herself to spank them. She'd endured too much of that as a child.

They seemed a happy couple. But like many blended families, the Diazes had arguments about disciplining 16-year-old Misty and Angel's 9-year-old son from a previous relationship. But what upset Lisa most was when Angel called her a hypochondriac.

Dr. Crowder spends hours quizzing Lisa about her many physical ailments. They began, Lisa says, with a flu shot in January 2002.

"Driving home, I got a horrible, horrible headache...one of the worst headaches I've ever had," Lisa says. "I kept telling everybody that it was [after] that flu shot that I started having all these symptoms...And then the other thing that happened was, I started to feel...like kind of scared, paranoid."

Lisa recounts a litany of complaints: stiff joints, headaches, pain in her kidneys, numbness, intense thirst, chills, sinusitis, fatigue, sore throats, weight loss and insomnia. Some of her symptoms were bizarre: She'd lie down to go to sleep and feel the backs of her eyes "shaking."

A few of the ailments could be readily identified: carpal tunnel syndrome and an injured ankle that resulted in surgery after Briana was born. But after the flu shot, Lisa visited multiple physicians--including an endocrinologist, rheumatologist, gynecologist, dermatologist, neurologist and orthopedist--to find out what was wrong with her. They ran blood tests and MRIs but could find no physiological cause of her pain.

One morning in February 2002, she awoke early feeling "like somebody was pushing on my head," she says. "And then, like my joints started hurting again, and I felt like I was going to pass out." She drove herself to a hospital where she was treated for dehydration.

A few days later, feeling she was having a heart attack, Lisa made another ER visit, calling paramedics when Angel refused to take her. She describes the attending physician as "really, really rude." After suggesting she might have a ruptured cyst, the doctor did a "really rough and hard" vaginal exam.

"[He] started doing all kinds of things down there, like, I could feel him, like, rubbing...he never even told me whether I had a ruptured cyst or not; he never even mentioned it." The doctor's diagnosis was "Oh, you're just having a panic attack." He prescribed an anti-anxiety medication.

Lisa was indignant. "I told him, 'I was asleep when all this happened...I'm not having a panic attack.' And he didn't want to hear anything I had to say to him." Lisa became convinced that the ER doctor had left something inside her. "It just seemed like for some reason he wanted to, like, somehow hurt me," Lisa says.

Doctors prescribed medications for Lisa; worried about side effects, she rarely took them. She tells Dr. Crowder that one antibiotic "made me really thirsty, and it made me...feel like my body was swelling up and like I couldn't go to the bathroom and like my tongue was...getting fat and my face looked fat...And it made me really paranoid and scared.

"If I'd go somewhere, people were staring at me and stuff," she continued. "And I had even told my husband...when I go to pick up my daughter from school, there's this lady...she always keeps turning around like that and she keeps looking at me, and I don't know why she keeps doing that."

She denies hearing voices of God or Satan or demons but admits that during an MRI scan of her spine, she heard the machine talking.

"What did it seem like it was saying?" Dr. Crowder asks.

"Open up," Lisa says.

Scouring the Internet for information about her symptoms, Lisa became convinced at various times that she had lupus, mad cow disease, internal worms, seizures, multiple sclerosis, thyroid dysfunction, tuberculosis and diabetes. She brushed off any suggestion that her symptoms were psychological, not physical. Lisa turned to alternative medicine, including acupuncture, Chinese herbs and homeopathic remedies.

Between January 2002 and September 2003, Lisa made 90 visits to doctors or alternative therapists for treatment. Her obsessive fear of germs grew worse. She washed her hands 10 times an hour. Convinced she suffered from ringworm contracted from her mother, Lisa noticed rashes on her daughters as well.

To cure the ringworm, Lisa began laundering the family's linens daily and spraying Lysol on everything they touched: doorknobs, light switches, faucets, mattresses, even pillowcases. Some things were so contaminated, she thought--such as pillows and hairbrushes--that she threw them away. For the rashes, Lisa rubbed mustard seed and papaya on the girls' skin and made them drink Chinese herb potions.

Lisa's feelings coincided with other pressures in her life. She defended Misty's problems in school and her adoption of Goth-style clothing against Angel's criticism. Lisa felt Angel couldn't see that his son bullied Briana and Kamryn. Most of all, Lisa felt angry that Angel wasn't taking her physical symptoms seriously. Angel would later testify that he "blew off" his wife's constant complaints.

Nothing Lisa did soothed her fears. Seeing similar symptoms in her children, Lisa believed she'd passed on her illnesses to them. Though not a churchgoer, Lisa felt there was a spiritual dimension to their sufferings. She turned to the Internet to learn about Kabbalah, a form of Jewish mysticism.

There she found concrete remedies. Lisa fashioned bracelets from red string and slipped them on the children's wrists, as recommended in Kabbalah to ward off the "evil eye"--negative energies transferred from the unkind stares of others. Lisa saw those kinds of looks from her neighbors, at school, when shopping.

To banish the evil spirits in her house, Kabbalah recommended sage. Lisa purchased the herb at a health food store and burned it throughout her home while reciting a mystical blessing. She washed her bad dreams off her hands each morning in the manner prescribed by Kabbalah.

On September 2, 2003, a frustrated Angel accompanied Lisa on yet another visit to Dr. Eduardo Wilkinson, a Richardson internist she'd seen several times before, beginning a year earlier. He would later testify that Lisa looked different during this visit: more anxious, very upset.

"She was deteriorating," Wilkinson said. "She was definitely worried about something." It could have been Angel's new job, which required travel. Lisa felt vulnerable to danger when her husband was gone.

After spending 40 minutes with her, Wilkinson suggested her problems were psychosomatic and referred her to Dallas psychiatrist Doyle Carson. Lisa agreed to follow up, but she never did. Her pain was physical, Lisa insisted to her husband, not in her head. Fed up, Angel refused to listen.

The day before the murders, Lisa threw away Misty's hairbrush, believing it was ringworm-infested. She remembers feeling anxious. "I believe we had to go to the Laundromat that day to go wash the blankets again," Lisa says.

That night, Lisa gave Briana some of the Chinese herbs to drink. The little girl balked. Angel, observing all of this, became angry.

"That's when he said that I needed to see a psychiatrist, because he said there's nothing wrong with them," Lisa tells Dr. Crowder on the videotape.

"I thought that he was the one that needed the psychiatrist, because he couldn't see the things that were obvious."

About six weeks after the killings, Angel Diaz visited the McKinney law office of Darlina Crowder. The attorney was impressed: Well-groomed, handsome, wearing a business suit, Diaz seemed like a successful executive. But he was still distraught. The first two times they met, Angel started bawling as he talked about his daughters.

"He didn't come in to hire me, but to get advice," says Ms. Crowder, who is also Hispanic (she is not related to psychologist Jaye Crowder). Angel wasn't happy with Steve Miller. Angel "wanted someone to keep in contact with him on a daily basis," Crowder says. Reassuring him that Miller was an excellent lawyer, Ms. Crowder sent Diaz on his way. But Diaz returned, determined to change counsel.

"As far as Angel was concerned, Lisa was a great mother," Ms. Crowder says. "He was devastated that his daughters were gone. But he loved his wife. To him, there were no signs that she would actually kill her children. He didn't come in and say, 'My wife is crazy.' He said, 'I don't know what happened. She's a good wife, a good mother. I come home, and my kids are dead.'" Lisa's oldest daughter, Misty, was supportive of her mother, too.

The Diazes didn't have financial problems or lots of debt. No one was having an affair. A mother of three children, Ms. Crowder had one thought: "Any mother who killed her kids has to have something wrong with her."

At that point, Ms. Crowder had been practicing law for six years. For such a big case, she had to bring in Robert Udashen. That afternoon, Ms. Crowder and Diaz drove to Dallas to meet with her mentor.

Udashen had made national headlines in October 1980 when he and veteran McKinney attorney Don Crowder successfully defended Candy Montgomery in the ax murder of Betty Gore. Their strategy was self-defense, not insanity. Gore had confronted Montgomery about an affair with Gore's husband and attacked first. The self-defense scenario, however, was problematic: Montgomery had struck Gore 41 times.

Udashen hired a psychologist to evaluate Montgomery. He determined she had flashed back to a childhood trauma and lost control when Gore told her, "Ssshhh." The case would eventually become the subject of a book and a movie.

It was Don Crowder, Darlina's father-in-law, who inspired her to go to law school. Days after Darlina passed the bar exam in November 1998, Don committed suicide. Ms. Crowder says that some people blamed his death on the Montgomery case. She doesn't.

"I think he was extremely proud he won the case," she says, "but I don't think he realized the severity of public reaction. A lot of the people in this county didn't care for him anymore."

After Don Crowder's death, Ms. Crowder turned to Udashen when she needed advice. (She divorced Don's son in 2002.)

Boyish and athletic, Udashen, 51, doesn't look much older than he did when he defended Montgomery. Since that case, he's developed a reputation as a lawyer's lawyer--great in the courtroom, good at appellate work and an excellent teacher--but before the Diaz trial, he'd handled only two insanity cases. He lost one; the other didn't make it to trial.

In Texas, the "not guilty by reason of insanity" defense is raised in less than 1 percent of all felony cases. And only 26 percent of the cases in which it is raised result in a NGRI verdict.

Texas Penal Code section 8.01 states: It is an affirmative defense to prosecution that, at the time of the conduct charged, the actor, as a result of severe mental disease or defect, did not know that his conduct was wrong. Though many criminals have mental conditions, the problem is the definition of two words, know and wrong.

According to University of Texas law professor George Dix, the right-or-wrong standard dates back to 1843, in the so-called M'Naghten case. British woodworker Daniel M'Naghten shot and killed a secretary during his assassination attempt on the prime minister. He was acquitted; doctors said that he suffered from what would now be called "delusions of persecution symptomatic of paranoid schizophrenia." Under M'Naghten, if the accused is unable to tell the difference between right and wrong at the time of the crime, he should be acquitted.

In the 1960s, a second "volitional" prong was added to Texas law, absolving a defendant if he acted on an "irresistible impulse." But after the acquittal of John Hinckley for the attempted assassination of President Ronald Reagan in 1982, more than 30 states, including Texas, eliminated that prong and tightened their insanity defense standards.

"Texas has one of the more restrictive definitions in the country," Udashen says. Periodically, the state Legislature looks at changing the law to "guilty but insane" but has taken no action.

As Udashen and Ms. Crowder talked to Angel, they became convinced that insanity was Lisa's only defense.

"On the other hand," Udashen says, "I knew what happened to Andrea Yates. That looked like a classic insanity case. And they lost. Lisa Diaz didn't have any of that. I knew it would be hard, but there was no other defense to raise."

Ms. Crowder took on the role Udashen had played years earlier, working with Lisa and other witnesses. Udashen focused on evidence and trial strategy. He had a risky decision to make: whether to use the videotapes of Lisa.

"If I decided not to use them, the jury wouldn't see them," Udashen says. "There was a lot of good stuff for me but also some bad things. In the first tape, she can answer questions. She doesn't seem insane." And on the last tape, when the questioner asks Lisa if she would have killed her children if a police officer had been present, she answers no. That might indicate to the jury that Lisa knew what she'd done was wrong.

While Udashen struggled with those questions, he brought in psychiatrist Doyle Carson and clinical psychologist Rycke Marshall to probe deeper inside Lisa's world.

Quizzing prospective jurors for the Lisa Diaz capital murder trial last August, Udashen and Ms. Crowder realized they were facing tough odds.

"People were saying, 'I would never find someone not guilty by reason of insanity if they killed their kids,'" Udashen says. "People didn't like the insanity defense. They didn't like psychiatrists and psychologists. They felt there were no standards." The judge excluded 40 of about 70 potential jurors for cause.

Lisa had remained on and off suicide watch. In January, Carson began treating her with anti-psychotic medications as well as anti-depressants. Though Lisa showed some improvement, she remained paranoid and suicidal as the psychiatrist struggled to find the right treatment approach.

Carson says psychiatry used to regard psychotic delusions such as Lisa's as psychologically based. He no longer believes that. "If someone is psychotic, I think it is a biological condition," Carson says. "I think it was a biochemical reaction operating inside of her. Things went awry somewhere in the central nervous system. I don't see people recovering from that kind of condition without medication."

Though the state wasn't seeking the death penalty, Lisa faced an automatic life sentence if convicted. Her psychotic fog had lifted enough for Lisa to contemplate her future. "She worried about ending up like Andrea Yates," Udashen says.

Udashen thought the surprising acquittal of Deanna Laney, whose Tyler trial in March 2004 was covered by Court TV, made his job harder. "I heard this from the jury panel: 'It's not right; she [Laney] got off,'" Udashen says. "There's this backlash that I had to deal with."

The defense team's confidence went up right before trial when two experts appointed by the judge filed their reports, offering the same diagnosis as the four expert defense witnesses: Lisa, at the time of the crime, was suffering from severe depression with delusional psychosis.

Tests run by psychologist Robert Lovitt indicated Lisa wasn't "malingering," or exaggerating her mental illness. She scored a "0" on a test for psychopathic traits, "indicating that she is not a callous, uncaring, manipulative and impulsive individual." Lovitt's conclusion: "It is highly likely that she was out of control and not adequately aware of the nature and implications of her alleged homicidal behavior."

Udashen spent hours studying the Yates case. "Because she had a lot of psychiatric treatment, they had a lot of different doctors who weren't consistent, and it was confusing for the jury," Udashen says. "The doctors I hired and the doctors appointed by the court were all consistent."

The defense got its biggest shock as the trial opened: Collin County prosecutor Greg Davis opted at the last minute to try Lisa only for the murder of Briana--meaning that if she was acquitted, Lisa could later be tried for Kamryn's death. It was the same strategy used in the Yates case.

Arguing that Lisa resented her husband and wanted to punish him, Davis called a paramedic and a nurse to testify about Lisa's demeanor after her arrest, attempting to show that she didn't meet the legal definition of insanity because she knew her actions were wrong. She didn't answer the door when her mother and Misty knocked. Lisa told Angel something "bad" had happened to the children. She told a jailer, "I'm so ashamed of what I did."

Subpoenaed by the prosecution to testify about going to her daughter's house that day and finding the doors locked and the blinds drawn, Cano painted Lisa's childhood in glowing terms.

After the prosecution rested, Ms. Crowder says, "some of the jurors looked like they hated us."

When psychologist Rycke Marshall met Lisa Diaz for the first time in December 2003, she saw a fragile, almost gaunt young woman. She'd lost 30 pounds in jail.

"I'm not sure I've ever been in the presence of someone whose pain was so palpable," Marshall says.

A stylish woman with close-cropped blond hair, Marshall spent five years in the late '70s as chief psychologist at Terrell State Hospital, where she was asked to testify in criminal trials. She now has a private practice in North Dallas. Of the four psychologists and psychiatrists who testified in Lisa's trial, Marshall's testimony lasted the longest.

In addition to reviewing the tapes and interviewing family members, Marshall spent about 20 hours talking to Lisa. "Andrea Yates would become immobile and non-functioning," Marshall says. "Lisa was quietly psychotic. She had a delusional disorder that is very unusual."

In all her years of practice, Marshall says, Lisa is the only patient she encountered who had no one she called mother. "It tells me about the absence of stability and predictability and healthy attachments in her life," Marshall says.

Contrary to her mother's rosy account, Lisa's childhood was a nightmare of abandonment and extreme emotional deprivation, Marshall testified. At her great-aunt's home, Michelle and Lisa slept on the floor. When she was 4, Lisa claimed, her great-aunt tried to smother her with a pillow. From then until she was 10 years old, Lisa often wet her bed and as punishment was sent to school in urine-soaked clothes.

When her mother came back into Lisa's life, she seemed like a stranger. "Lisa was very hopeful that her mother is coming to rescue her and Michelle," Marshall says, "but come to find out, it's at least as bad." Marshall would testify that Rosemary Cano was high-strung and demanding. The girls often went without food or clothes.

"The mother gets involved in drugs, leaving them in the car while she's in the clubs," Marshall says. "The girls are pretty much left to their own devices." Cano later spent time in prison on a drug charge.

Never part of her life, Lisa's father also did prison time. Showing up when she was 13, Lisa's father took his daughter for visitation, got drunk and forced her to perform oral sex on him. Marshall says that when Lisa talked about her father, "she was very sad, very frightened and very anxious, as if it said something bad about her." A bizarre visit by her father to the jail after Lisa's arrest, in fact, triggered a suicidal episode.

During her abusive first marriage, Marshall says, Lisa began to manifest depression, anxiety and a preoccupation with physical problems.

"When people are confused and have feelings they can't make sense of, they look for an anchor somewhere to explain it," Marshall says. "She has been abandoned so many times I imagine she has had this kind of depression all her life. When people begin to be delusional, they focus on some false belief. That becomes the glue that holds them together."

Though things improved when she married Angel, Lisa still faced the ordinary pressures of life: marital conflict, child-rearing problems and illness. Lisa fixated on the physical to explain her misery.

"There's the hope if it's something physical, it can be fixed," Marshall says. "Of course, the flu shot had nothing to do with it. It simply coincided with a time she was feeling bad. As she became more and more depressed, which is partly a biological process, she became more and more focused on it being a physical problem until she developed a full-blown delusional disorder."

In the week before Lisa killed, Marshall says, she started drinking her own urine, a bizarre remedy she read about on the Internet.

"The things she does over time are more and more unusual and psychotic," Marshall says. "Then we're into omens and voices in her head telling her, 'You have to die.'" When Marshall asked Lisa who or what the voices were, she replied: "It was like the voice of doom."

After Laney's acquittal, Udashen sought advice from the Tyler woman's attorney. "They had a videotape that Dr. [Phillip] Resnick had made of Laney," Udashen says. "He convinced me that if I had that, to use it." The tapes would give Lisa a way to testify without going on the witness stand and would allow the jury to see her state of mind.

During Lisa's trial, Udashen played excerpts from each tape. At first Lisa is coherent, but she disintegrates in tapes seven and eight as the questions focus on the day she killed her children.

After driving Briana to kindergarten and buying a new hairbrush to replace the one she'd tossed, Lisa took Misty to school. When her daughter pointed out two crows on the lawn, Lisa took them as an omen that she and the girls must die that day.

At home, Lisa straightened up the house. Voices in her head said, "This is the day you have to do it. Today's the day you have to die." The family dog wouldn't come to her. Another sign.

But Lisa didn't make the final decision until she talked to Angel on the phone that afternoon. He told her about a child who could talk to family members killed in a car accident. To Lisa, that was the final signal.

Lisa piled Kamryn into the Durango, and they drove to Target. She bought pillows to replace those she'd thrown away, a "Polly Pocket" toy pool and dolls for each little girl, and three kitchen knives.

At home, Kamryn played with her toy. At 2:45 p.m., Lisa went to school to pick up Briana, who also came home and played with her toy. Lisa noticed dark circles under Briana's eyes, a sign she was terribly sick.

"And after Briana played with the toy?" Dr. Crowder asks on the viedeotape.

Lisa's answers are whispered, often inaudible. Tears stream as she describes drawing water in the tub in the bathroom off the master bedroom, telling Briana she needed a bath. Lisa sobs as she describes how she brushed the sage over Briana's body and said a prayer--"Dear God, please take care of my precious angel"--and pushed her under.

"Can you remember what was in your mind at that time?"

"I just felt that I had to save them," she whimpers.

"What were you saving them from?"

"So they wouldn't have to suffer anymore."

"What kind of suffering?"

"From their health and..."

"Health and what?"

Lisa's eyes glaze over. "Just because..." She rocks and rubs her shoulder, unable to answer.

"What else were you protecting them from...Was it the demons?"

"It was just the evil spirits. I had to save them...I was scared."

Lisa tells how she put Briana on the bed and covered her with a blanket, then ran water for Kamryn. She repeated her prayer and drowned Kamryn.

With her dead children lying on her bed, Lisa got the knives she'd bought at Target, stripped and entered the shower. Lisa stabbed herself 20 times in the chest, stomach, neck and wrists before giving up. She later required 37 stitches.

With eight minutes left on the tape, Crowder asks Lisa, "Is there anything else you want to tell us?"

"I wish this had never happened," she whispers.

"What is most on your mind when you say you wished it had never happened?"

She looks up in anguish. "Because I miss them so much."

The jury took 12 hours to find Lisa Diaz not guilty by reason of insanity. At first the jurors were split, and they spent most of their deliberations watching the videos. "The tape let them see her say why she did it," Udashen says. On the second day, the last holdout juror voted not guilty.

Concerned about the discrepancy in the Yates and Laney verdicts despite the similar evidence, the Texas Senate Jurisprudence Committee held a hearing in 2004 on changing the insanity defense statute to include "guilty but insane" as a possible jury charge. Other changes to broaden the legal definition of insanity--taking into account the current understanding of severe mental illness--have been proposed, but for now have gone nowhere.

Under Texas law, someone found NGRI is subject to commitment in a state hospital. How long Lisa stays is up to trial court Judge Mark Rusch. She now lives at the Vernon campus of the North Texas State Hospital, the same facility where Laney is being treated. The two women have met.

Yates remains in a prison psychiatric unit despite the appellate court ruling overturning her sentence. The Harris County District Attorney's Office has said it will appeal.

"I don't think these three women were that different," says UT professor Dix. "Although there were differences, it didn't bring to bear on their culpability or blameworthiness, whatever Park Dietz thinks."

Udashen worries how Lisa will cope once she understands her actions. "It's a Catch-22 to bring them out of their mental illness so that they realize what they've done."

The Diaz jury was told that 500 women a year kill their offspring. "It's not so rare," Darlina Crowder says. "We just don't hear about it all the time."

Between them, Yates, Laney and Diaz killed nine children.

http://www.dallasobserver.com/2005-01-20/news/psycho-mom/full#comments