Ashley Cecilia Castaneda, 31, told police about the gun as she was being driven to the station after police found nearly 30 grams of methamphetamines and a set of digital scales in her purse on Monday.
"They pulled to the side of the road, the officers got out, asked her where the gun was, and the female said, `it`s between my legs`," Patrick Swanton, police sergeant, told KWTX news.
"It could have been extremely dangerous for everyone involved."
The bizarre incident is not as unusual as people would think, he said.
"People don`t believe this happens in real life," he said. "It happens much more than the average citizen would ever know."
It was not clear if the safety was engaged on the .22-caliber Smith & Weston when she placed it in her body.
The gun weighs about six ounces (170 grams) and is just under 5 inches (12 centimetres) long - about the length and weight of an iPhone 6 with a thick case.
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