Michael Brewer, 15, spoke for the first time with investigators Monday from his room at the Jackson Memorial Burn Center in Miami, the Broward County Sheriff's Office said.
"He gave a complete statement that should prove very helpful," sheriff's spokesman Jim Leljedal said, declining to release details of Brewer's statement.
Brewer was burned over two-thirds of his body after several teenagers allegedly poured rubbing alcohol on him and then set him on fire.
Denver Jarvis and Matthew Bent, both 15, and Jesus Mendez, 16, have pleaded not guilty to a charge of attempted-murder. Two other teenagers initially accused in the attack have not charged, though prosecutors said the case has yet to be finalized, The Miami Herald reported Tuesday.