The mother-in-law of one of the grown children, Nancy Markham, said Byrd and Melanie Billings were found in the bedroom of their home in Beulah, just west of Pensacola near the Alabama border.
Escambia County Sheriff's officials told the Pensacola News Journal that all the children living in the home were found safe following the Thursday night attack. The children were home at the time and "deputies had to wake some of the children," said sheriff's office spokesman Sgt. Ted Roy.
The children at the home ranged in age from an infant to 11 years old, he said.
According to a 2005 profile of the couple in the News Journal, some of the adopted kids included children of drug users, sexual abuse victims and children with developmental disabilities.
"They were very good people. I don't know what's going to happen to those children," Markham told the News Journal.
Authorities were searching for three men in a red van who may have been involved in the slayings, authorities said. Investigators were also examining surveillance tapes from the home. The suspects forced their way into the home, authorities said.
The couple owned several local businesses and had been featured in the News Journal for their generosity taking in children with disabilities and from troubled backgrounds.