A Texas babysitter is in a San Antonio jail after being accused of sexually assaulting a 4-year-old boy.

Esmeralda Medellin, 18, is charged with sexually assaulting a young boy while she was babysitting in March. Her arrest by police in San Antonio follows the results of DNA tests officials say confirms her sexual contact with the boy, the San Antonio Express-News reported on Sunday.

The boy’s mother called police after her son told her Medellin made him perform a sexual act on her while she cared for him in the mother’s absence, according to reports. Police took Medellin and the little boy to a hospital for a sexual assault examination. Following the exam, police transported Medellin to the station for questioning where she denied the boy’s allegations. Police released her at the time, pending the results of the medical tests.

On August 16, tests reportedly confirmed DNA samples taken from Medellin’s breast matched that of the boy. Another sample confirmed male DNA on Medellin’s genitals. Police said they were unable to retrieve enough of a sample from her genital area to get a positive match.

The test results gave police enough evidence to move forward and on August 17, police took the babysitter into custody.

Medellin now faces a charge of suspicion of aggravated sexual assault. Police took her to the Bexar County jail where she is being held pending a $75,000 bond.

No information was immediately available on future court proceedings.

Bob Price serves as associate editor and senior political news contributor for Breitbart Texas. He is a founding member of the Breitbart Texas team. Follow him on Twitter @BobPriceBBTX and Facebook.