DENVER (CBS4) – The Denver District Attorney’s Office has declined to file criminal charges against a female Transportation Security Administration agent at Denver International Airport after a passenger complained the pat-down she received amounted to sexual assault.

“I felt sick to my stomach,” said Jamelyn Steenhoek, 39, when she learned Wednesday that Denver prosecutors were no longer pursuing her complaint and would not be filing criminal charges.

“Those TSA agents were purposely abusive to me,” said the Highlands Ranch mother. “And there isn’t any recourse. I still feel as if a crime was committed, and as an individual American I am powerless to do anything about it.”

Steenhoek was at DIA on Dec. 26 escorting her 13-year-old daughter to a flight. Steenhoek herself was not boarding a flight that day, but she still had to clear security to take her daughter to the concourse and gate.

Steenhoek said that when a female TSA agent patted her down, “She cupped my crotch … the part of the search that bothered most was the breast search. You could tell it shouldn’t take that much groping. To me it was as extensive as an exam from my physician … full touching and grabbing in the front. I felt uncomfortable, I felt violated.”

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Three days later Steenhoek, who works for a county social services department and is working towards a college degree, filed a complaint with the Denver Police Department, asking that the female TSA agent who frisked her be charged with sexual assault.

She says a detective contacted her Wednesday to tell her the case was not accepted for prosecution by the Denver District Attorney’s Office.

“I don’t understand how a reasonable person would think that this behavior is acceptable,” Steenhoek said.

Lynn Kimbrough, a spokesperson for the Denver District Attorney’s Office, told CBS4 that because of the nature of the case it was reviewed by two deputy district attorneys who agreed the investigation should be dropped with no charges filed.

“We would be unable to prove it beyond a reasonable doubt,” Kimbrough said.

Specifically, she said prosecutors believed they could not prove touching of Steenhoek by the TSA agent was for gratification, arousal or abuse — elements of a sexual assault charge.

The TSA did not immediately respond to an email from CBS4 seeking comment on the district attorney’s decision not to file charges.