Just 20 years old, Valles Garcia is a college student majoring in criminology.
She was the only person who wanted the dangerous job where officers have been abducted and even killed.
"It's something I believe in, something we want to see happen," Valle Garcia said.
Her small Mexican town of 8,500 people, just south of Brownsville, Texas, is ground zero in a deadly drug cartel turf war.
Just this past weekend, the former mayor and his son were executed while hiding out in nearby Ciudad Juarez, the bloodiest city in Mexico with a reported 2,500 people killed in drug violence this year alone.
That danger has some doubting whether the young chief can handle the job.
Valles Garcia said she signed up for the tough task to help her community.
"We've received a lot of good feedback within the community and positive criticism," Valle Garcia said.
She plans to use her largely female police force to rebuild trust between authorities and residents.
She said they won't carry guns and will focus more on crime prevention.
In a city battered by drug violence, where so many have been forced to flee, the young chief is already winning respect for her willingness to stay and stand her ground.
When asked if she is afraid, Valles Garcia said yes, that it's only natural. But she said she hopes to change that fear into security for everyone in her frightened town.