Store employees observed that the vehicle was having issues parking and then they noticed that the driver did not appear to be old enough to have a license.
"It was just odd the way they were driving it," Walmart employee Roy Hoover told the News Herald. "He was having a hard time parking it, like he'd never drove one before."
Michael Wade Propst apparently found the door of the bus unlocked and the keys in the ignition, so he decided to take it for a spin. Propst's driving skills were impressive.
"You have to take a weeklong course to operate a bus like that," said Bay District School's chief security officer, Mike Jones. "Yet at 12 he was able to drive one, and he didn't just take it around the block."
Propst has been charged with grand theft of an item worth more than $100,000, felony criminal mischief and additional crimes.
When police contacted Propst's mother, she asked police to reason with the boy because "she was not having any impact on him."