(CNN) -- Eleven women and two men have been selected to hear the case of the alleged ringleader of a group of "ninjas" who shot and killed a Florida couple known for adopting special-needs children.
The jury, which includes one alternate, was selected Monday in the trial of Leonard Gonzalez Jr. Prosecutors said that he and six others put on black masks and dressed as ninjas before creeping into the Beulah, Florida, home of Melanie and Byrd Billings on July 9, 2009.
Opening statements are set for Tuesday morning in Escambia County Circuit Court in Pensacola, and the trial is expected to last three to four days. Gonzalez, 35, could be sentenced to death if he is convicted of first-degree murder.
Prosecutors accuse Gonzalez of shooting and killing the couple in their bedroom while one of their special-needs children looked on. The Billingses cared for 13 special-needs kids, nine of whom were home at the time.
Officials say the "ninjas" entered the home in hopes of stealing the family's safe, which they believed contained upwards of $13 million.
A small safe containing prescription medication, family documents and some jewelry was taken and later was found in the backyard of a woman who said she was a friend of Gonzalez's, authorities have said. Two sources familiar with the investigation said a second safe at the home contained at least $100,000.
Of the eight people arrested in the case, seven males faced charges of murder and home invasion robbery. Two of them have pleaded guilty to second-degree murder charges. The woman is accused of being an accessory after the fact.
The remaining males, including a 16-year-old charged as an adult, have pleaded not guilty to the charges.
Escambia County Sheriff David Morgan has said Gonzalez once worked for a car dealership that Byrd Billings owned, and court documents state that Gonzalez received financial support from the family for a martial-arts studio that he ran.
An attorney representing the Billingses has said that Byrd Billings made a nominal donation to Gonzalez's karate charity.
A nurse who works with special-needs children interviewed the child witness, who has autism and speech issues, regarding the deaths of the Billingses. The nurse told police that the boy said "two bad men" were wearing black masks when they knocked on the door. It was unclear from the interviews whether he meant the bedroom door or the front door of the home.
They woke Byrd Billings and told him, "You're going to die," the child said.
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.
The children's accounts were contained in hundreds of pages of documents released by the state attorney's office as part of the pretrial discovery process.
Also in the documents is a July 22, 2009, police interview with Gonzalez, who told authorities that a group of car dealers did not like Byrd Billings and had gotten together to discuss this.
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.
CNN InSession's Nancy Leung and Jean Casarez contributed to this report.