Psycho Mom

"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.

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."

"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.