The family-of-four found dead at the million dollar Florida home of former US tennis star James Blake, were shot, authorities say.
A man, his wife and their two teenage children were shot before the home they were renting from the retired athlete burned down in an apparent arson attack, it was revealed Friday.
Authorities recovered a gun at the house, belonging to the father who died in the blaze – who had bought an “exceedingly large amount” of fireworks and gas cans days beforehand.
Authorities have said they think Wednesday's fire at the mansion north of Tampa was started deliberately, but they have not said who started it, Sky News reported.
No suspects are being sought, but police have stopped short of calling it a murder-suicide.
Authorities have not released the identities of the dead, but family members named them to US media as Darrin Campbell, his wife Kimberley and their teenage children Megan and Colin.
Mr Campbell is said to have bought more than a dozen fireworks on Sunday.
His purchase included firecrackers and aerial fireworks, according to the vice president of Phantom fireworks, William Weimer, who spoke to US media by phone from the firm's Ohio headquarters.
Emmy-winning TV reporter Meredyth Censullo said in a tweet that an unnamed source told her the bodies “had heavy duty fireworks wrapped around their heads”.
Neighbours told police they heard explosions coming from the home in the exclusive gated community of Avila.
Hillsborough County Sheriff's officer Donna Lusczynski said "various fireworks" were found throughout the home.
Two of the victims had "upper body trauma", police said, an expression often used to describe gun or stab wounds.
The children's bodies were found in their bedrooms and the two adults were discovered in their bedroom.