Boy, 16, Among 7 Arrested in Mysterious Murder of Florida Couple

Seven suspects, including a 16-year-old boy, have been taken into custody for their alleged involvement in the July 9 murders of a Florida couple who had 16 children, most of them disabled kids they adopted.

"Seven individuals are currently in custody related to the murders of Bill and Melanie Billings," said Escambia County Sheriff David Morgan at a press conference Tuesday.

Hugging the couple's eldest daughter, Ashley Markham, who is now the family matriarch, Morgan reassured her, "We have found them, they are in custody."

VIDEO: Police search for more suspects and a motive in the murder of a Florida couple.Play

There were "no direct ties" between the alleged murderers and the slain couple but at least some of the individuals arrested had been on the Billings' property in the past, said Morgan.

One of the suspects, Leonard P. Gonzalez Sr., 56, owned a pressure washing business and had hired three of the suspects as day laborers as he needed them, according to Morgan. Gonzalez Sr. is believed to have been the group's getaway driver, according to Morgan.

The four other suspects, including the 16-year-old, had worked at an auto detailing business in nearby Okaloosa County.

VIDEO: Suspects are charged in the slaying of a couple who adopted special needs kids.Play

Wayne Coldiron, 41, one of the seven suspects arrested, had been on the Billings' property "at least one time," said Morgan.

It was not immediately clear what type of work Coldiron had performed for Byrd, 66, and Melanie, 43, Billings.

Leonard P. Gonzalez Jr., Gonzelez Sr.'s son, was a "pivotal" player in the operation, according to Morgan.

All seven will likely be charged with an open count of murder and the juvenile will be treated as an adult, said Florida State Attorney Bill Eddins.

Gonzalez Sr., who was initially charged with tampering with evidence for allegedly trying to disguise the red van that police believe was used as the getaway vehicle, is likely to see his charge increased to an open count of murder as well.

VIDEO: Abandoned van may hold new clues to crime scene in murder of Florida couple. Play

There is still one more local individual that has yet to be arrested who police say was involved in the crime after it occurred. Morgan declined to say when an arrest of this individual might occur.

Eddins confirmed that the main motive in the crime was robbery.

"They did take items that you would normally expect to be taken in a robbery," said Eddins. A medium-sized safe was taken from the home, according to Eddins, who declined to specify what was inside the safe.

Since the murders last week, police have repeatedly characterized the suspects' operation as having "military precision."

Today, Morgan confirmed that some of the individuals in custody do have a history of military service.

"We have info that indicates there was a good amount of practice that was involved," said Morgan. "It was very a well-planned and well-executed operation."

The suspects were on the Billing's property for 10 minutes and were in and out of the house in less than four minutes, Morgan said.

Two teams stormed the house on Thursday evening from different entrances and successfully navigated the large home before allegedly shooting and killing the Billings.

Nine of the couple's children were in the house at the time.

One team of two men entered the front of the house while another team of two men, all dressed in black ninja gear, entered through an unlocked back door of the home, he said.

Morgan speculated that one man may have been responsible for disabling the security system, but failed, allowing investigators to use surveillance videos to identify several suspects.

Federal agencies with video-enhancing capabilities have been assisting the investigation by reviewing surveillance video from the Billings' home as well as local stores where the suspects are believed to have purchased the ninja garb they allegedly wore during the incident.

"This was a well-planned, methodical operation," Morgan said. "There was planning that went into this operation."

In a surveillance tape from the Billings home that Morgan called "chilling and shocking," two men emerge from among trees in the rear property and hurry to a back door of the house.

They are believed to have been traveling in a metallic blue flake or gold flake Escalade that has not yet been located.

Detectives have been viewing surveillance tapes from local merchants such as K-Mart, Target and Wal-Mart in hopes of spotting some of the assailants buying clothing used in the assault, Morgan said.

Asked why the Billings family may have been targeted for this robbery, Morgan speculated that it may have had to do with the family being well-known in the community.

"The 'why question' in any crime that occurs is one you wrangle with," the sheriff said. "It could be a very long time before we know why this family was selected."

The deaths of the Billings couple shocked the country because they had dedicated their lives to caring for disabled children. They had four children of their own, but adopted 12 others, including children with Down syndrome and cerebral palsy.

Ashley Markham, one of Melanie Billings' biological children, said the children were coping with their parents' death.

"The children are coping very well," an emotional Markham said during a news conference Monday. "They are with lots of family and friends are not asking a lot of questions."

Byrd Billings managed several businesses that allowed him and his wife to be able to take care of so many children.

Morgan described him as an entrepreneur who "was involved in a lot of different businesses."

A memorial for the Billings will be held Friday morning, with a burial to follow.