Despite routine visits, state investigators repeatedly missed clues that the children were being abused in their new home.
In the days since the children were found, the state has removed two other children, a girl named Jennifer, 7, and a boy named George, 11, from the Barahonas' home and placed them in protective foster care.
Carmen's biological granddaughter, who made frequent visits to the Barahona home, told a school therapist about the twins' abuse, saying the children had been bound and forced to stand in a bathtub. The therapist then called a child abuse hotline.
The state's Department of Children and Families has come under increased scrutiny for failing to remove the children from the home, despite signs of abuse.
A case worker in 2007 wrote: "Nubia's hunger has been uncontrollable, she sneaks and steals food, steals money, has hair loss, is very thin, nervous and jittery. Nubia also has an unpleasant odor… In the past it is believed Nubia's adoption was halted when Nubia was coming to school dirty while in the adoptive mother's care."
"This child is very medically needy and should not be missing appointments because the foster parent does not want to take her," the report said.