"The ball struck her in the back of the head, at the base of her neck," said Lieutenant Trent Colledge.
The tragedy has been described as a "freak accident" especially since the golf cart was not stopped directly in front or behind Hill, but rather 45 to 90 degrees to the left.
"It's an extremely tragic accident," Colledge added.
"I can't imagine what that father is going through."
Aria Hill (front) with her family. Her dad Kellen Hill hit a golf ball, which struck the six-year-old and killed her. Photo / Facebook
Aria's uncle, David Smith, told local TV station KSL Aria was her dad's "golfing buddy".
"She loved doing it and had a good time with it all," he said.
"That was one of their things that they would do together. It was something that was really important to them and something they did all the time."
A GoFund Me account set up to pay for Aria's funeral expenses has already raised more than $22,000.
"We are so grateful for all the love, support, and prayers made in our behalf during this difficult time," her mother Talysa said in a statement.
"We've truly felt comforted. Aria was the sassiest girl in the world. She was silly, spunky, creative, unique, and so, so full of love for everyone she came in contact with. There is a huge hole in our hearts that she has taken with her back to Heaven … Fly high my little angel."