(CNN) -- With his nine special-needs children in his house and one of them with him in the master bedroom, a Florida man was on his knees when an armed intruder shot him in the face, then fired twice more after the victim had fallen face down on the floor, a medical examiner said Wednesday.
Byrd Billings died execution-style the night of July 9, 2009, as did his wife, Melanie, after a band of people dressed as ninjas broke into their Beulah, Florida, home. Prosecutors say Leonard Gonzalez Jr., 35, led six other men into the house looking to steal an expected $13 million and personally killed the defenseless couple.
Dr. Andrea Minyard testified Wednesday, the second day of Gonzalez's first-degree murder trial in Escambia County Circuit Court in Pensacola. She pinned needles on human-sized dummies to show how nine bullets hit the Billings' couple.
Video footage aired earlier in the trial showed a masked, armed man hovering over a shirtless Byrd Billings in the palatial home's living room shooting a shirtless Byrd Billings twice, with one shot in each leg.
Frederick Thornton -- part of the group who testified after pleading guilty to second-degree murder -- fingered Gonzalez as the man who fired the shots, then led the couple into the first-floor bedroom.
After shooting Byrd Billings the first time, Gonzalez said "where's the money at, and he told him to get up," said Thornton, 20.
Defense attorneys dispute Thornton's assertion, claiming he's not a credible witness and saying another masked man fired the shots.
The Billingses had 16 cameras around their home, set up to keep tabs on the nine special-needs children for whom they cared. There was no camera in the master bedroom, but prosecution witnesses Wednesday cited DNA tests as showing that Gonzalez likely handled the rifle used in the fatal shootings.
One of the videos aired in court Tuesday shows the scene from one girl's bedroom as a red van packed with people arrives outside the house. The girl gets up out of bed as the masked men enter the house, then hides under the covers pretending to sleep after hearing the commotion nearby.
The team had started, then called off, an armed invasion at the home on July 4. Before the second try, Rakeem Florence -- who, like Thornton, plead guilty to second-degree murder for his role and testified for the prosecution -- said there was no mention anyone would be killed until he overheard Gonzalez minutes before they went to the house.
"He said he was going to kill somebody," Florence, now 18, said of Gonzalez.
Florence and Thornton claimed Gonzalez captained the scheme, leading pre-invasion meetings, supplying the firearms and all-black clothing, and ordering they destroy the clothing afterward.
Florence testified that he was told the plotters were trying to get laundered cash believed to be in a safe at the house, as the Billings family was "washing money from the Mexican mafia."
Defense attorneys for Gonzalez questioned the credibility of the two witnesses, since they are related (Florence is the father of a child born to Thornton's sister) and had changed the stories they told their family and police, saying they had "practiced lying."
Also Wednesday, the jury of 11 women and two men saw prosecutors try to establish the guns used in the crime, as well as see the safe taken from the Billings' home.
Prosecutors say a small safe containing prescription medication, family documents and some jewelry was later was found in the backyard of a woman who said she was a friend of Gonzalez, authorities said. Two sources familiar with the investigation told CNN that a second safe at the home contained at least $100,000.
The defendant's wife, Tabitha Gonzalez, testified Tuesday that the family's business, a karate school, had gone under. Byrd Billings had even donated $5,000 to the Gonzalez's school.
Prosecutors argue this indicates that financial gain was Leonard Gonzalez's overriding motive in the armed invasion.
"He was so broke ... that his mother had to buy him a car, which turned out to be a big red van that was used in the murders," prosecutor Bill Eddins said in his opening statements of Gonzalez, who had six children with Tabitha.
Of the eight people arrested in the case, seven males faced charges of murder and home invasion robbery. Two of them have already 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.
If convicted, Gonzalez could be sentenced to death.
In Session's Jean Casarez and Nancy Leung contributed to this report.