A family of four found dead in a suspected arson at the Florida home they were renting from a former tennis star had been shot, investigators have said.
Post-mortem examinations are still being completed to determine how the man, his wife and their two teenage children died, but investigators have said they are looking into the possibility of a murder-suicide.
A gun was recovered at the house registered to Darrin Campbell and he had also bought an “exceedingly large amount” of fireworks and petrol cans the day before the fire, Hillsborough County Sheriff's Colonel Donna Lusczynski said.
Authorities said that fireworks and petrol had possibly contributed to the fire, but did not indicate who may have started the fire or why.
The deceased have not yet been formally identified, but the family has not been accounted for and a relative said they were inside the home when it set ablaze on Wednesday morning.
Mr Campbell bought $650 (£380) worth of fireworks on Sunday and authorities said fireworks were found throughout the five-bedroom property.
But it was not clear what role the fireworks might have played, though Col Lusczynski said they could have been used to ignite the fire or keep it going.
Mr Campbell had been an executive for several high-profile businesses. He was currently working at a records management firm and volunteering as treasurer at his children's private school. His wife Kimberly was a stay-at-home mother, according to her father Gordon Lambie.
The family moved to Tampa more than a decade ago. They sold their home in 2012 for $750,000 (£445,000) and signed a two-year lease for the 6,000 square-foot home owned by former tennis pro James Blake. He bought the home in the Avila community in 2005 for $1.5 million (£88,107), according to property records.
Mr Lambie said the family wanted to move closer to the children's school, Carrollwood Day School.
Nineteen-year-old Colin Campbell was a talented baseball player who planned to graduate from high school next month. His teenage sister Megan was a ninth-grader who made an honour roll and took dance lessons.
Mr Lambie said from his home in Michigan: “I've lost my entire family. It's very tough right now because I'm 1,500 miles away.”
Additional reporting by agencies