The 9-year-old boy who snuck onto a plane without a ticket has had several brushes with the law.

On Thursday, the boy, who has not been identified, got through security at the Minneapolis-St. Paul International Airport and boarded a Delta Airlines plane headed for Las Vegas, without presenting a boarding pass. Now, the Star Tribune reports that, before this latest incident, the boy had stolen a car and snuck into a water park, prompting child protection investigators to undertake four "child-protection assessments" on the boy’s family.

The paper also reports that authorities are investigating whether the boy's mother helped her child get on the plane to Las Vegas, since she works at the Minneapolis airport.

The Associated Press reported on Sunday that, before the boy boarded the flight on Thursday, he went on a test run of sorts the day before. On Wednesday, the boy traveled to the airport, grabbed a random bag from the baggage carousel, ordered lunch at an airport restaurant and skipped out on the tab.

Once the flight crew realized the boy was not supposed to be aboard the plane, they contacted police, who met the child at the gate and took him into protective custody.

A Delta spokesperson told NBC News the airline is investigating the incident.

“Delta continues to work with authorities and look into the circumstances involving an un-ticketed minor boarding an aircraft in Minneapolis-St. Paul,” Delta spokesperson Leslie Scott said.

“Safety and security are always Delta’s highest priorities and we are reviewing our policies and procedures to make sure something like this does not happen again.”l