It was a mistake.
"Soon as I jumped out and went inside, I left the door unlocked, and they jumped in and took it," he told ABC11 Eyewitness News.
Chavis said he saw three boys get into the 5,000 pound SUV and take off.
Raleigh police public information officer Jim Sughrue said officers spotted the Expedition with two boys inside around 10:30 a.m. near Enloe High School and followed it into the school parking lot.
The two boys ditched the SUV near the school's front entrance and took off on foot.
Officers quickly caught the driver, who they said turned out to be an 11-year-old. ABC11 and police aren't naming him because of his age.
The passenger got inside the school. Officials quickly put the entire building on lockdown while police searched for him. About 30 minutes later, they arrested 16-year-old Deandre Jacquaris Woodin in the cafeteria.
The 11-year-old has been charged by juvenile petition with possession of a stolen vehicle, with resisting, delaying or obstructing a law enforcement officer and with operating a vehicle without a license.
Woodin has been charged with possession of a stolen vehicle and with resisting, delaying or obstructing a law enforcement officer.
Neither boy is charged with actually stealing the Expedition, and the investigation continues.
After police recovered the SUV, Chavis showed up at the school to claim it.