Detectives arrested a man and a Tacoma woman earlier this week after text messages sent on an airplane prompted an investigation of child sexual exploitation and rape.

One passenger onboard a July 31 flight from Seattle to San Jose, Calif. contacted authorities when their plane landed Monday. Police said the witness observed disturbing text messages that included comments about the sexual exploitation of children.

The phone was oversized and had a large font that enabled the witness to see it. San Jose police detained the suspect and detectives from the Internet Crimes Against Children Task Force took over the investigation.

The recipient of the man's text messages was tracked to a woman in Tacoma. Detectives also discovered the woman had access to children either as a caregiver or babysitter, police said.

Authorities in San Jose contacted Seattle Police ICAC investigators, which is the lead ICAC task force in Washington state. A Seattle Police Department detective tracked down the Tacoma woman at her home.

Police said she lived with her ex-husband, his wife, and three kids. A search warrant was served on the woman's home as well as the male suspect's home.

Police identified two children, a 5-year-old and a 7-year-old, as victims.

Detectives interviewed the female suspect and booked her into Pierce County Jail for sexual exploitation of a minor, first-degree rape of a child, and Dealing in depictions of a minor engaged in sexually explicit conduct while the investigation continues.

The man was arrested for two counts of attempted child molestation and two counts of solicitation of a sex crime.

The case is highlighting the need for bystander awareness when it comes to the prevention of human trafficking and child sex exploitation.

"It gives me a lot of hope that the passenger knew to step in and say something," said Mar Brettmann. "I mean that could make the difference in the lives of these children."

Brettmann founded a Seattle non-profit called BEST, or Businesses Ending Slavery & Trafficking that focuses on bystander training and awareness.

"My biggest tip for a bystander is if something goes off in your head as a red flag that something might be wrong in a situation, especially involving a child - it could be trafficking, it could be child abuse, it could be a number of things, but tell somebody who can help," she said. "Whether it's law enforcement or a staff member somewhere, just let someone know what you're seeing.

It's advice she frequently gives to employees of hotels, where human trafficking takes places far too often.

Brettmann praises both the alert plane passenger and the Southwest Airlines employees for their quick thinking in this recent case.

"I do think people are becoming more aware of what human trafficking is," she said. "But I still talk to people all the time who think sex trafficking victims are brought from overseas, they don't think it happens to our own kids in the United States. And it does."

In the greater Seattle area, it's estimated as many as 500 children are bought and sold for sex every year. Some are as young as 11 years old. Most are from the United States, and are bought in hotels.

If you see something that concerns you, you can also call the National Human Trafficking Resource Center. It's available 24 hours a day, seven days a week at 1 (888) 373-7888.

The King County Prosecutor's Office is reviewing this recent case and working with the U.S. Attorney's Office to determine if charges are necessary in Washington state or if federal charges are appropriate.

Related resources:

Washington State - Human Trafficking

National Criminal Justice Reference Service

Polaris Project

The Campaign to Restore and Rescue Victims of Human Trafficking under the US Dept. of Health and Human Services

Shared Hope International

Washington Anti-Trafficking Response Network (WARN)

Seattle Against Slavery

International Association of Chiefs of Police

Tronie Foundation