Will Alleged Killer Mom Be a Wake-Up Call?

May 15 -- Like the friends and relatives of Andrea Yates, the Houston mother convicted of killing her children, Deanna Laney's neighbors never believed she would — or could — ever harm her sons. But Yates' attorney hopes Laney's case will sound a new alarm.

"Andrea is a wake-up call," Yates' defense attorney, George Parnham, told ABCNEWS.com. "Deanna LaJune [Laney] is another shakeup … like a car that's been left on the side of the road."

Laney, 38, is charged with two counts of capital murder and one count of aggravated assault. Police say that on Mother's Day weekend, Laney beat her two older sons — Joshua Keith, 8, and Luke Allen, 6 — to death with stones the size of dinner plates, then attacked 14-month-old Aaron James, all while her husband was asleep in their Tyler, Texas, home. Aaron remains hospitalized in critical condition with an open skull fracture.

Given that she allegedly killed her two elder sons 14 months after her youngest was born, Laney may not have suffered from postpartum depression at the time of the slayings, Parnham said. But that doesn't mean that she didn't suffer from the condition, and that it went undiagnosed and developed into psychosis, he said.

"It [Laney's case] speaks volumes about mental illness," said Parnham. "I'm not saying that she [Laney] suffered from postpartum depression because I just don't know. But it doesn't mean that she was not psychotic at the time she did what she did to them [her children].

"It's so hard for the husbands and the doctors … women can somehow mask the signs of [severe] postpartum depression and hide them from their peers, doctors and their husbands."

A Post-Conviction Mission

The slayings shocked Laney's relatives, friends and neighbors. There had been no previous reports of domestic violence or child abuse, and unlike Yates, Laney had never been diagnosed with or treated for depression or postpartum depression.

But they may share the same murder defense — insanity. In Laney's first court appearance Monday, her court-appointed attorney, F.R. "Buck" Files — who has consulted with Parnham — told the judge, "I'm not sure if she can truthfully say she understands what is going on."