(Douglas C. Pizac ~ Associated Press)
In each case, as in many others every year, the alleged or convicted perpetrator had been the boyfriend of the child's mother -- men thrust into father-like roles they tragically failed to embrace.
Every family is different. Some single mothers bring men into their lives who lovingly help raise children when the biological father is gone for good.
Nonetheless, many scholars and social workers who monitor America's families see the abusive-boyfriend syndrome as part of a broader, deeply worrisome trend. They note an ever-increasing share of America's children grow up in homes without both biological parents, and say the risk of child abuse is markedly higher in the nontraditional family structures.
Existing U.S. data on child abuse is patchy, making it hard to track national trends with precision. The latest federal survey on child maltreatment tallies nearly 900,000 abuse incidents reported to state agencies in 2005, but doesn't delve into how abuse rates correlate with parents' marital status or the makeup of a child's household.
Similarly, data on the roughly 1,500 child-abuse fatalities that occur annually in America leaves unanswered questions. Many of those deaths result from parental neglect, rather than overt physical abuse. Of the 500 or so deaths caused by physical abuse, the federal statistics don't specify how many were caused by a stepparent or unmarried partner of the parent.
However, there are many other studies that reinforce the concerns. Among the findings:
* Children living in households with unrelated adults are nearly 50 times as likely to die of inflicted injuries as children living with two biological parents, according to a study of Missouri data published in the journal of the American Academy of Pediatrics in 2005.
* Children living in stepfamilies or with single parents are at higher risk of physical or sexual assault than children living with two biological or adoptive parents, according to several studies co-authored by David Finkelhor, director of the University of New Hampshire's Crimes Against Children Research Center.
* Girls whose parents divorce face significantly higher risk of sexual assault, whether they live with their mother or father, according to research by Robin Wilson, a family law professor at Washington and Lee University.
"I've seen many cases of physical and sexual abuse that come up with boyfriends, stepparents," said Eliana Gil, clinical director for the national abuse-prevention group Childhelp.
"It comes down to the fact they don't have a relationship established with these kids," she said. "Their primary interest is really the adult partner, and they may find themselves more irritated when there's a problem with the children."