Escambia County Sheriff David Morgan said he wants to talk with several more persons of interest and likely would make one more arrest before winding down the investigation, CNN reported Monday.
Byrd and Melissa Billings were fatally shot July 9 in their home in Beulah, Fla., near Pensacola, during a home-invasion robbery in which a safe containing prescription medication, family documents and jewelry was taken. Nine of the couple's adopted children were in the house at the time.
Morgan did not provide any more details about another possible motive for the home invasion but did say the wife of one of the suspects contacted police and would be interviewed.
"We are making very delicate moves," Morgan said. "We are very concerned about any misstep that we may take or that we may make that would jeopardize the successful prosecution of the individuals we currently have in our custody."
So far, seven people have been charged with murder in the couple's deaths. An eighth person was charged as an accessory after the fact.