(CNN) -- The son of a Florida couple known for adopting special-needs children was in his parents' room when they were slain in a home invasion last month, according to documents released by prosecutors.
Leonard Patrick Gonzalez Jr., 35, is one of seven people charged with murder.
A nurse who works with special-needs children interviewed the boy, who has autism and speech issues, regarding the deaths of Byrd and Melanie Billings. The nurse told police that the child said "two bad men" were wearing black masks when they knocked on the door. They woke Byrd Billings and said, "You're going to die."
The child, whose age was not given, said one of the men counted to three "before he shot mom and dad," and his father kept screaming, "No way, no way."
Byrd Billings grabbed the back of one man's neck and struggled with him before he was shot, the child said. The boy said Melanie Billings "got shot in her shirt."
Another child told the same nurse he was upstairs in bed and stayed in his room when he heard the knock on the door. The second boy recalled hearing "seven booms" and crept into the hallway. He heard Melanie Billings scream, he said, but stayed upstairs until police arrived.
It was unclear from the interviews whether the men knocked on the bedroom door or the front door of the home.
The Billingses were shot and killed July 9 in their Beulah, Florida, home. Seven males are charged with first-degree murder and home invasion robbery. An eighth suspect, a woman, faces a charge of being an accessory after the fact. The seven males, including a 16-year-old charged as an adult, pleaded not guilty to the charges last week.
The children's accounts were contained in hundreds of pages of documents released this week by the state attorney's office as part of the pretrial discovery process.
Also in the documents is a police interview with Leonard Patrick Gonzalez Jr., 35, one of the seven suspects and the man police believe was the organizer of the slayings. Two of the other suspects told authorities he was the lone gunman, according to court documents.
Gonzalez told authorities in a July 22 interview that a group of car dealers did not like Byrd Billings and had gotten together to discuss the problem. Used car dealer Henry "Cab" Tice came to him, Gonzalez said, and told him the group wanted Billings killed, but he refused to do it.
Another son of Billings told police that a man named "Cab" had "double-crossed" his father and that the son was present when the two men argued.
Tice has been questioned but not charged in the slayings. He is charged, however, with one count of grand theft for allegedly writing a series of bad checks to Billings, authorities have said. Various interviews in the documents point to a close relationship between Tice and Gonzalez.
Also released by prosecutors was a transcript of a police interview with Tice in which he acknowledged accepting a $20,000 loan from a man he later learned was connected with the Mexican Mafia. Tice said he was told his family could be killed if the money was not repaid. Police had previously said Tice was believed to owe the Mexican Mafia money.
Contacted by CNN Tuesday, Tice refused comment. But in an interview Monday with CNN affiliate WEAR, Tice said Gonzalez's comments about him constitute an "act of a desperate man."
"There is nobody that I know in Pensacola that would want to see Bud Billings killed," Tice told WEAR, using Billings' nickname. "There are business people in Pensacola that are upset with him, that were upset with him, but nobody that I know would want to see Bud Billings killed."
The Billingses each had two biological children and had adopted 13 children. Police have said nine of the children were home during the slayings and several were believed to have seen the gunmen. One child managed to flee the home and seek help from a neighbor.
Autopsy reports also were released. They showed that the Billingses were shot multiple times. Byrd Billings also had a white zip tie on his left arm, according to the report.
The eighth suspect in the case, Pamela Wiggins, was taken back into custody Monday after her bond was raised from $10,000 to $500,000. Authorities said they found a safe belonging to the Billingses in Wiggins' backyard. That safe contained prescription medications, family documents and jewelry and was taken from the home during the slayings.
Family members have since confirmed that a second safe was in the home and that it contained $164,000, antique jewelry and legal documents. The second safe was not taken.
The released documents also said that safe contained a sealed hard drive, a detail not previously revealed. The Billings family agreed to allow authorities access to that hard drive, according to the documents.
Prosecutors believe there were dual motives in the killings: robbery and a contracted hit, a source with knowledge of the investigation told CNN last month. The source said prosecutors were working under the belief that most of the suspects in the case were told only that they were robbing the Billingses, but that Gonzalez and other yet-unnamed suspects also were plotting to kill the couple. The source was not sure of the alleged motive behind the slayings.
Escambia County Sheriff David Morgan has said publicly his office believes a contract hit was a possibility. The state attorney's office said last month it was focusing on the robbery, but was willing to consider other motives.
CNN's Ross Levitt and Carolina Sanchez contributed to this report.