Insanely Guilty

"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."

"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 Diaz 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 Diaz a way to testify without going on the witness stand and would allow the jury to see her state of mind.

During Diaz's trial, Udashen played excerpts from each tape. At first Diaz 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, Diaz took Misty to school. When her daughter pointed out two crows on the lawn, Diaz took them as an omen that she and the girls must die that day.

At home, Diaz 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 Diaz 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 Diaz, that was the final signal.

Diaz 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., Diaz went to school to pick up Briana, who also came home and played with her toy. Diaz noticed dark circles under Briana's eyes, a sign she was terribly sick.

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

Diaz's answers are whispered, often inaudible. Tears stream down as she describes drawing water in the tub in the bathroom off the master bedroom, telling Briana she needed a bath. Diaz 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?"

Diaz'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."

Diaz 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, Diaz got the knives she'd bought at Target, stripped and entered the shower. Diaz 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 Diaz, "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 they 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 Diaz 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 Diaz 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."

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