It was a crime that shocked everyone. A father abducts his five and three-year-old sons and then drowns them.

"It's a shame, an absolute shame of what that guy did," Dallas resident Elvin Jones said.

The next day, a Forth Worth man upset with his girlfriend abducts her four-year-old daughter. She's found a few hours later alive and well.

"I'm just glad that they caught him and that he can't do nobody else like that, no matter who it is," the child's grandmother Annette Sanders said.

Both of the men arrested in these cases had abusive relationships with the mothers -- with histories that included assaults and in both cases, the women had broken up with the men.

Kelly Slaven-Terstreip is a counselor at Genesis Women's Shelter" href="">Genesis Women's Shelter. She says these cases are about men losing power and control of the women -- so they use the children as pawns.

"Children are the most important thing to mothers, we know, and they are the quickest way to get back at her if there is an ongoing domestic violence situation," she said.

"When he's gotten to that point, he's desperate to hurt her in a way; and he's not caring about the consequences anymore, which makes him especially dangerous because he has nothing left to lose," she said.

You may recall the Battaglia case in 2001, when a Dallas father who was also abusive had his two daughters call their mother and then shot the girls to death while the mother was on the phone.

Attorney Patrick McLain handles domestic violence cases. He says it's still rare for a father to kill his own children.

"Typically, the man will either commit violence against the wife or the girlfriend or against someone who is a love interest for the wife or the girlfriend," he said.

But if the man harms the children, he says it's more likely the man is no longer mentally stable.

"Very seldom is a person in a rational state of mind, and he simply clearly thought out a cold calculating crime. Typically they have some sort of serious mental disease or defect," he said.