A mom and her biracial child were stopped by police at a Denver airport because a Southwest employee suspected human trafficking

• A white mom and her biracial daughter, 10, were stopped by police for suspected human trafficking at a Denver airport.
• The pair was reported to police as "suspicious" by a Southwest Airlines flight attendant.

A white California mom and her biracial 10-year-old daughter were stopped by police for suspected human trafficking after a Southwest Airlines flight attendant reported the pair as "suspicious" - an incident the mother called "racist harassment."

Mary MacCarthy, 42, told Insider that she and her daughter, Moira, boarded a Southwest Airlines flight from Los Angeles to Denver with a connecting flight in San Jose on October 22 in order to be with her family following the sudden death of her brother.

When the single mom and her child got off the plane at Denver International Airport, they were immediately met by two Denver police officers and a Southwest representative on the jet bridge at around 2:30 p.m, according to police records and partial cell phone video footage of the incident seen by Insider.

MacCarthy, a former journalist who works in the tech industry, said she was told she had been "reported to the pilot for suspicious behavior."

"As a mother to a biracial child, it immediately clicked in my brain," she told Insider. "I assumed we had been reported for trafficking."

In a video taken by MacCarthy in which her daughter can be heard crying, a Southwest employee tells the mother the pair were stopped because employees were "just concerned about the behavior when you boarded the aircraft."

According to a police report from the Denver Police Department, officers were sent to the airport over a "report of possible Human Trafficking reported by Southwest Flight Attendant."

The police report states that a Southwest attendant on the connecting flight told authorities that "the mom and daughter did not talk during the flight and she felt that it was odd and also the mother did not allow the child to talk to flight crew."

MacCarthy denied this claim as an "outright lie" in a later email to investigators, saying her daughter spent much of the flight listening to an audiobook and that they had spoken during the trip.

After speaking with police officers, both MacCarthy and her daughter were ultimately "cleared" to go, according to the police report.

MacCarthy said she believes they were racially profiled.

"I have a 10-year-old biracial daughter who was going through the worst day of her life from the death of her beloved uncle, and then she has to deal with armed police," MacCarthy told Insider. "I consider that racist harassment."

MacCarthy said she only later learned from a follow-up call with a detective ten days later on November 1 that there was an official "suspicion of human trafficking."

"As far as I was concerned everything was immediately cleared up that day [on October 22]," she said. "And if you're really going to go after potential human traffickers, take it seriously, don't just make a casual phone call ten days later."

Southwest said in a statement to Insider on Thursday that the company was "disheartened" by MacCarthy's account of events.

"We are conducting a review of the situation internally, and we will be reaching out to the customer to address her concerns and offer our apologies for her experience traveling with us," the statement read.

"Our employees undergo robust training on human trafficking," the airline added. "Above all, Southwest Airlines prides itself on providing a welcoming and inclusive environment for the millions of customers who travel with us each year."

MacCarthy wrote in an email to Southwest after the incident that officers told her she was "reported for 'suspicious behavior prior to boarding in San Jose' and that we 'had boarded suspiciously late.' "

MacCarthy, who has hired an attorney, has demanded an apology from Southwest Airlines and a reimbursement of her and her daughters' plane tickets.

"I have yet to be contacted by Southwest with anything more than an automated response. And at this point, I want Southwest Airlines to be held accountable for having racially profiled my family on what was objectively already the worst day of my daughter's life," MacCarthy said.