Russell Yates was an "unemotional" husband who didn't do enough to address his wife's mental illness in the days before she drowned their five children, the mass-murderer mom's mother and brother said Monday.

As Andrea Yates was formally sentenced to life in prison for murdering three of the children, her family said Russell Yates deserves some of the blame for their deaths.

Yates' brother, Brian Kennedy, called Russell Yates, an "unemotional" husband inattentive to his sister's needs.

"I think that any man and woman whose spouse was that severely down, confused, that sick, that I would do whatever it would take to make sure my other half would get the help that was necessary," Brian Kennedy said in a group interview with Houston television station KTRK.

Tonight, on On The Record, tune in for Greta Van Susteren's interview with Sgt David Svahn, one of the first police officers to arrive at the Yates home on the day of the murders.

Yates' mother, Karin Kennedy, said her son-in-law told her after the birth of their fourth child that he had never changed a diaper.

"When they came to my house, that was the first time I told Rusty, 'Luke needs changing,'" Kennedy said. "He says, 'Well that'd be a first. I have never changed a diaper before.'

"And that was the fourth child. I was horrified."

Asked about criticism of his role, Russell Yates told NBC's Today show Monday that some people "don't understand the biochemical nature of Andrea's illness ... so they'll say there must have been something else going on in that household, or there must have been this or that and it's all false."

And he told CBS's The Early Show that he is considering suing the doctors who took his wife off antipsychotic medication before the killings.

"I think I have to," he said. "She was never diagnosed, she was never treated and [the doctors] didn't protect our family." Andrea Yates had been treated for schizophrenia and severe depression after the births of her last two children.

But Brian Kennedy said Russell Yates — not the doctors — was to blame. "How many people have begged him, noticed that she was in a downward spiral?" Kennedy said in the interview, which was broadcast on ABC's Good Morning America. "And he is going to sit there and point the finger at the medical community. How many people and what kind of people have to tell him? 

"Myself and others had actually almost begged and tried to educate him . . . to loosen up and lighten the load that she was under, but instead it seemed like it just kept increasing, increasing and increasing," Kennedy said.

The family members spoke out Monday morning as Yates, 37, was formally sentenced to life in prison. According to Texas law, she must serve 40 years before she is eligible to ask for parole.

"Good luck to you, Mrs. Yates," state District Judge Belinda Hill told the killer, who wore an orange Harris County jumpsuit instead of the civilian clothes she wore during her four-week trial.

Defense attorney George Parnham requested that Yates stay at the Harris County Jail for as long as possible to continue receiving medical care. When she arrives in the Texas prison system, she will join 69 other women serving time for killing one or more of their children.

Yates was convicted of capital murder last week in the June 20 attack on her children after a jury rejected her insanity defense. The same jury took less than an hour Friday to reject lethal injection, meaning Monday's life sentence was automatic.

Several of the jurors said the way Yates drowned her children seemed premeditated and methodical.

Juror Leona Baker told CBS' The Early Show that a "couple" of jurors initially voted for death, then the jury discussed it and became unanimous on the life sentence.

"I believed that she was not going to be a threat to society being in prison for the next 40 years of her life," she said.

On the NBC Today show Monday, juror Melissa Ryan said, "I think she should be punished for what she did considering she did know right from wrong and I think prison's the way to go."

A juror identified on NBC's Dateline as Jill, a social worker, said as Yates explained to police how she drowned the children, it seemed as if she was "thinking pretty clearly."

One of the jurors pointed to Yates' decision the night before to drown the children and the organized manner in which she went about holding each child beneath the water's surface before calling in the next.

When she finished, Yates called police.

"She was able to describe what she did ... I felt like she knew exactly what she was doing, and she knew it was wrong, or she would not have called the police," said a juror identified by Dateline as Roy, a math teacher.

The jurors on the Sunday broadcast of Dateline said they started by considering what they found to be the most compelling evidence — the videotaped confession to police and photographs of the children, alive and dead.

Yates could have faced the death penalty based on the two capital murder convictions for the drowning deaths of Noah, 7, John, 5, and 6-month-old Mary. Evidence also was presented about the deaths of Paul, 3, and Luke, 2.

The jurors said they believed Yates was mentally ill, an opinion shared by both the prosecution and the defense, but they also believed that she knew right from wrong — a key element in determining whether a defendant meets the legal definition of insanity.

"Andrea Yates, herself in her interviews, said she knew it was wrong in the eyes of society," Jill said. "She knew it was wrong in the eyes of God, and she knew it was illegal. And, you know, I don't know what wrong means if all those three things aren't factored in."