LAKEWOOD, Wash. -- A 9-year-old boy from Lakewood sneaked past security and talked his way onto a Southwest Airlines flight at Sea-Tac Airport Monday night after running away from home.

The boy’s mother told KIRO 7 Eyewitness News the family had been planning to move back to Dallas but when they delayed the move, the boy became determined to return.

“He just made a decision and said, 'I'm going to get there.' Well, how he got there is a wonder to me,” the boy's mother told KIRO 7 Eyewitness News.

According to the boy’s mother, the boy had stolen three cars in the last month trying to get to Dallas.

“I didn't help him get on a plane. I didn't give him any money to get on a plane. He's only 9,” the boy’s mother said.

Discuss: Sneaking On The Plane

He flew from Sea-Tac to Phoenix, where he tried to board another flight headed for Dallas, but was not allowed on the plane, so instead he got on another flight bound for San Antonio, where he is now being held.

Before the boy was able to get on the plane he had to get a boarding pass at the airline’s ticket counter.

Southwest Airlines would not consent to a recorded interview but told KIRO 7 Eyewitness News it’s investigating the incident.

"It's definitely something we're looking hard into. We honestly don't know what happened,” airline spokeswoman Marilee McInnis told KIRO 7 Eyewitness News.

According to Southwest Airline's website their unaccompanied minor policy states children between 5 and 11 years old are accepted only on nonstop or direct flights with no change of aircraft or flight number.

A TSA spokeswoman said passengers are allowed through screening without showing identification if the airline issues them a boarding pass.

The boy had been arrested twice including Sunday night after leading Lakewood police on a high-speed chase on state Route 512, KIRO 7 Eyewitness News reported.

According to the boy’s mother, she has asked for help with her son but Pierce County juvenile authorities have refused to hold him in custody because he is too young.

Lakewood police are seeking a warrant for the boy’s arrest and are asking authorities in Texas to keep him locked up so he won’t run away again.