The reputation of foster care has become so bad that few may have noticed when New York City’s Department of Investigation reported last month that the Administration for Children’s Services was failing to ensure the safety of foster children. Of course, it is not hard to find headlines about foster parents accused of abusing kids. Earlier this year Jennifer and Sarah Hart drove their S.U.V. off a Northern California cliff, killing themselves and at least four of the six children they had adopted, probably out of the foster system. Last year, Cesar Gonzales-Mugaburu was acquitted after spending a year in prison on a charge of endangering or sexually abusing eight of the nearly 100 boys he had fostered in his Long Island, N.Y., home. In Duchesne County, Utah, a foster mother was charged this month in the death of a 2-year-old boy in her care.

Stories like these buttress the widely held misperception that children are most likely to be abused by strangers and that those in foster homes are therefore uniquely vulnerable.

But if you read past the first paragraph of the New York City investigation, you come upon this startling fact: A majority of the maltreatment incidents (which include cases of both abuse and severe neglect) happened while foster kids were visiting their biological parents. Foster parents were the perpetrators in just 19 percent of maltreatment incidents last year.

That’s terrible, but more disturbing is that children who have been removed from their parents’ homes because of abuse or neglect are then brought back to visit or stay with those parents. And they are subject to physical or sexual abuse all over again.