Two men being held on murder charges in a wealthy Florida couple's killings went to their house intending to rob it, according to arrest warrants.

The suspects were due in court Monday, a day after they were arrested by authorities probing the shootings that occurred while eight of the couple's children slept in the house. Day laborer Wayne Coldiron, 41, turned himself in to Escambia County authorities and Leonard P. Gonzalez Jr., 35, was arrested in neighboring Santa Rosa County, Escambia County Sheriff David Morgan said.

Earlier Sunday, authorities charged Gonzalez's father, Leonard P. Gonzalez Sr., with evidence tampering. Police said the 56-year-old tried to paint over and hide damage on a red van that was spotted on surveillance video leaving the home where Byrd and Melanie Billings were shot to death Thursday.

More arrests are expected, and more charges could be added for those already in custody.

The elder Gonzalez told investigators that he was the getaway driver and waited in the van while the others broke into the house Billings' house and robbed it, according to the warrants released late Sunday. He also told police several other men were involved.

The surveillance video shows three armed, masked suspects arrive in the van, enter the house and then return to the vehicle, the warrants said.

The Billings, who were known for adopting children with developmental disabilities, were killed in their spacious, nine-bedroom home in a rural area west of Pensacola near the Alabama state line. The house had an extensive surveillance system that authorities said captured the break-in. Tips from the public led police to the van Saturday.

Morgan said the investigation involves a complex web of relationships between suspects, though he declined to elaborate on them. He said it did not appear that the suspects knew the victims. The younger Gonzalez and Coldiron are friends, the warrants said.

"We are very anxious to share this story ... it's going to be a humdinger, I'll tell you that," Morgan said earlier in the day.

The Billings had 16 children, 12 of them adopted. The children who were there during the killings, ages 8 to 14, were interviewed by police and are now staying with other family members.

The couple married 18 years ago and each had two children from previous marriages. They eventually started adopting children with developmental disabilities and other problems.

The house was carefully designed to accommodate the children, according to a 2005 story in the Pensacola News Journal. A camera was in every room, and the driveway was long to keep the kids from running into the street. A large swimming pool behind the house was gated.

The couple told the newspaper they wanted to share their wealth with children in need, but didn't imagine their family would grow so large.

"It just happened," she told the newspaper. "I just wanted to give them a better life."

Coldiron was expected to appear in court Monday. Because the younger Gonzalez was arrested in a neighboring county, he will have to appear there first.

They were charged with open murder because the investigation is ongoing and more charges may be added, Morgan said.

The charge of open murder does not require prosecutors to choose between first- and second-degree murder at arraignment or trial, but instead leaves it to a jury to decide the appropriate degree of the charge."

Bond for the elder Gonzalez was set at $250,000. A message seeking comment was left at a phone number listed for him in the Pensacola area.