Driven To Kill?

When Marva Wallace was sentenced to 25 years to life for shooting her husband to death, her children were little more than babies.

"They were 3 and 7 when I first went in," she says. "They're now 21 and 25."

Now, as CBS News Correspondent Bill Whitaker reports, after 17 years in prison, she's been set free. A Los Angeles judge ordered a new trial.

Wallace is the first woman released under a ground-breaking state law to help at least 100 women like her: battered women convicted of murder before 1992. That was the year California legitimized the "battered woman syndrome" defense.

They can now seek a new trial with expert testimony not heard the first time: that they could have been driven to kill.

"The kicking and the punching and pulling out my hair," Wallace remembers. "It got really bad."

"I know killing someone - that was wrong," she says. "I was afraid that if I hadn't killed him, he would have killed me."

Why would someone live like that?

Dr. Nancy Kaser-Boyd, a battered women syndrome advocate, helped convince the judge that Wallace's original jury needed to hear that women can be terrorized by beatings and threats.

Women stay in abusive relationships, Kaser-Boyd says, because men will often threaten to kill them or take the children if they leave.

"And that's the number one reason women don't leave: fear," she says. "Hitting you, raping you at gunpoint, knifepoint, whatever; It's OK," she says.

At the southern California prison where Wallace was locked up, battered women have regular meetings. Valere Boyd got 15 to life for killing her abuser.

"I tried to call the police on him one time, and he ripped the phone out of the wall and beat me so bad that I couldn't walk for a week," she says

Boyd says when Wallace walked out of jail it gave all of them hope.

"It's like she cracked open the gate a little bit," she says. "For so long the door has been closed on us."

But Wallace's freedom is no slam dunk.

Even with a new trial and new defense, Los Angeles district attorney says the old evidence still could put Wallace back in prison, says Los Angeles Deputy District Attorney Hyman Sisman.

"Her obvious planning and deliberation in the commission of the crime and her attempt to cover it up would not be something that could be explained away to any significant degree by a battered women's expert," Sisman says.

"I don't know what's gonna happen in the future, I'm just thankful to share this day … with my son and grandson," says a crying Wallace.

The law allows women like Wallace a new day in court. Whether battered women's syndrome will change the verdict, the jury is still out.