"We will be looking at who this firearm belonged to, where this firearm was in the vehicle at the time of the shooting, along with who was present when this child was shot," said Roy Rutland of Miami-Dade police.
"Obviously those kids will be interviewed as well, and that is a very, very important component to this investigation as well," Rutland noted.
Every year, more than 30,000 people are shot and killed in the United States, and the year 2012 was a record-setting year for gun sales in the country. About 4.5 million firearms are sold annually in the US.
Police in the US city of Miami say a 4-year-old girl was fatally shot while she was sitting in a car, and detectives are trying to determine whether another young child inside the vehicle fired the gun.
Miami-Dade Police said Rahquel Carr was shot in the upper body Saturday at about 6:10 p.m. (local time) as she was waiting in the car outside her grandfather's Miami home.
"Someone called my daughter and told her she (Rahquel) got shot and we're going to the hospital," said Sonya Wheelers, the girl's godmother.
The girl was airlifted to a hospital where she was later pronounced dead by police.
Police officials said there were at least two other children in the car at the time of the shooting and investigators were looking into the possibility that one of them may have accidentally pulled the trigger.
They also said that an adult was standing nearby outside.