Updated

Three more suspects were arrested Tuesday in the carefully orchestrated home-invasion murders of a wealthy Florida Panhandle couple known for adopting special needs children, the sheriff said.

That brings to seven — six adults and one juvenile — the total number of people arrested in the deaths of Byrd and Melanie Billings, said Escambia County Sheriff David Morgan.

"We have found them, and they are in custody," Morgan told reporters and the couple's sobbing adult daughter, Ashley Markham, Tuesday afternoon. He called the robbery "well planned" and "well executed."

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There is at least one more person at large suspected of "aiding and abetting" in the crime, Morgan said.

The Billings were known for adopting children with developmental disabilities and other special needs.

They were shot to death early Thursday evening in their home near Pensacola. Nine of the couple's 17 children were home at the time and three saw the intruders but were not hurt.

Masked suspects, some dressed as ninjas, stole a safe and other items during the deadly break-in at the couple's sprawling Florida Panhandle home.

"Last Thursday, tragedy occurred ... (and) we witnessed the worst in man: hatefulness, cruelty and indecency," Morgan said.

Three people — two adults and the 16-year-old juvenile — were caught Tuesday. Three suspects had already been arrested over the weekend and a fourth on Monday evening.

"The primary motive was robbery," said prosecutor Bill Eddins. Morgan had earlier said that there were multiple motives for the crime.

Authorities would not say what was in the safe or what else might have been taken from the house.

Morgan said investigators were still looking for at least one more person in the case and at least one of the suspects in custody may have done work at the Billings home. He has previously said the suspects had no direct connection to the victims.

One of those arrested Sunday, 35-year-old Leonard P. Gonzalez Jr., was a Pensacola martial arts instructor. He and his wife, Tabatha, received a Service to Mankind Award in June from the Pensacola Seville Sertoma Club for their work in teaching self defense to children and abused women.

Gonzalez and his wife had as many as six young children and brought them to the self-defense presentations, said Gwinn Corley, a spokesman for the Sertoma club.

"We were impressed with them," Corley said. "He was talking about children and their respect for their elders. They both seemed to have a passion to teaching the arts to abused women and kids, they had a vision for how to give free self defense."

Several of the suspects were day laborers who knew each other through either a pressure washing business or a car detailing group, Morgan said.

The arrests started Sunday with 56-year-old Leonard Gonzalez Sr., who was originally charged with evidence tampering but will be charged with murder, authorities said. He is accused of driving a red van seen on surveillance video pulling away from the Billings home and then trying to paint over it.

His son, Gonzalez Jr., was also arrested Sunday along with day laborer Wayne Coldiron, 41. Both were in court Tuesday to face murder charges.

Another day laborer, Gary Lamont Sumner, 31, was arrested on a murder charge in a nearby county Monday after he was pulled over in a traffic stop. Morgan said investigators have placed Sumner at the scene, though he would not provide details.

Three more people were arrested Tuesday — a juvenile whom police did not identify; Frederick Lee Thorton Jr., 19; and Donnie Ray Stallworth, 28, who was arrested in Alabama but lives in Florida.

The break-in was captured by an extensive video surveillance system the Billings used to keep tabs on their children.

Surveillance video showed three armed, masked men arriving in the red van, entering through the front of the house and then returning to the vehicle. Others dressed in what the sheriff called "ninja garb" went in through an unlocked utility door in the back. They were in and out in under 10 minutes.

"I think you'll find this particularly chilling and here's why: We have a team that enters at the rear of the home and another that enters at the front of the home," Morgan said. "It leads me to believe this was a very well-planned and methodical operation."

Morgan said, however, that there was no indication anyone had unlocked the door for the intruders, adding that people in the community felt comfortable leaving their doors unlocked.

The couple owned several local businesses, including a finance company and a used-car dealership. They lived in Beulah, a rural area west of Pensacola, near the Alabama state line, in a house set deep in the woods. They had 17 children in all — 13 of them adopted.

Tips from the public led police to the van on Saturday.

The Associated Press contributed to this report.