Psycho Mom

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.

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Glenna Whitley