A 13-year-old girl from Katy is reportedly still in Mexico after she ran away from home to connect with a man she met online.

Investigators say she took a bus to Laredo, the walked across the border.

Related: Sheriff: 13-year-old Katy runaway found before it was 'too late'

The bus ticket was paid for by a stranger in Katy who thought she was helping an 18-year-old in need.

“The story that was presented was that she was up in Houston visiting her boyfriend and was trying to work her way home and find a bus ticket to make her way back to her family. That was the story the perpetrator had set up for her. It was actually quite the opposite,” said Debi Tengler.

Tengler works with children who are victims of sex trafficking through Arrow Child & Family Ministries.

Luckily, the middle schooler from Katy was found safe Sunday night, but Tengler says so many runaways are still in trouble.

There are several situations to look out for.

“You may see a young child with an older male, and they don’t have a father-daughter, father-granddaughter relationship," Tengler said. "There’s a lack of familiarity that’s there. The child may appear nervous. They may be with two to three children at the same time, yet they’re not acting like teenagers should, for example.”

If possible, take a discrete picture.

However, experts say to not intervene.

“If you suspect anything is going on, it’s not your job to further investigate it. It’s your job to report it,” Tengler said.

Suspicious behavior can be reported to the National Human Trafficking Hotline at (888)-373-7888.

“Become equipped, know what the red flags are, and know how to make the difference in the life of a child who you may never get a chance to meet again,” Tengler said.