Manatee County deputies say the 16-year-old had been critically injured in the shooting that happened last Tuesday at a home in the 900 block of 14th Street East.
The sheriff's office had initially been told by a witness that the victim had accidentally shot himself in the head while holding a gun, but during the investigation, deputies said the teen's 15-year-old friend was playing with a gun when it accidentally went off and a bullet struck the 16-year-old.
"When deputies arrived, the other teenagers were trying to assist their friend, they were visibly upset they were trying to do what they could to save his life," said Randy Warren, a public information officer with the Manatee County Sheriff’s Office.
The teen suspect was arrested and charged with attempted manslaughter. Now that the victim has died, his charges have been upgraded to manslaughter, according to the sheriff's office.
"We have every reason to believe based on the interviews from those witnesses that this was an accident, a tragic accident, but there's unfortunately still consequences to go with it," Warren said.
Investigators are still trying to figure out where the gun came from and how the teens got it.