It was a terrifying surprise: Two men burst into the bedroom of Byrd and Melanie Billings and brutally murdered the Florida couple, execution-style, as one of their beloved disabled children watched in horror.
According to 700 pages of court documents and witness interviews released on the Billings case, the child in the room that day -- one of the couple's 13 special needs children -- used sign language to tell police he heard a knock on the door before the two men entered.
The child told police he heard one of the men say, "You're gonna die -- one, two, three." The boy said his father then grabbed one of the suspects and that his mother got shot in the shirt.
When it was over, Byrd Billings was found inside the master bedroom, shot six times, including twice in the back of the head, in what police believe may have been a contract hit. His wife, found in the hallway outside her bedroom, had been shot five times, including three times in her head.
The alleged ringleader of the operation, Leonard Patrick Gonzalez Jr., told police that his involvement was "very deep," according to the newly released documents and that he wanted to "talk to the Feds about this."
Investigators told ABCNews.com earlier this month that at least one source told police that the couple were the targets of a contract killing. They were murdered July 9.
"Early on in this investigation we had an uncorroborated statement from this individual that it could have been a contract killing," said Escambia County Sheriff David Morgan. "We have pursued and continue to pursue [this possibility]."
Morgan declined to clarify the individual's relationship to the case, other than to say that the statement was made to police "during the course of the investigation." He would not say if corroborating evidence to support the statement had been found. The Billings were well known for having adopted and cared for 13 special needs children.
While police continue to investigate the possibility of a contract killing, the sheriff's office is working with the state attorney to build a case against the eight individuals already charged in connection with the crime, seven of whom are charged with the Billings' murder.
"Everybody is concerned that nothing be done to jeopardize the existing case," Morgan said.
Police have repeatedly said that robbery was the prime motive for the deadly crime that was executed with "military precision." A single safe was taken from the home during the robbery and was later revealed to hold only some jewelry, children's medication and family documents.
"The one motive that we know, and is prosecutable... is that it was a home invasion, a robbery and a murder occurred. Those things are very definitive. When you get in the realm of, 'Was there an additional motive?' therein lies the conundrum," Morgan said.
Nine of the Billings' children were in the home when their parents were killed.
Byrd Billings was a 66-year-old entrepreneur who dabbled in used cars and boats before finally hitting it big. Melanie Billings was a 43-year-old country music lover who fed the homeless and was devoted to her MySpace page.
Together, they adopted 13 children with autism, Down syndrome or other developmental disabilities and lived in a sprawling home west of Pensacola.