SAN ANTONIO – Investigators with the Bexar County Sheriff's Office have arrested an off-duty detention deputy on a felony charge of sexual assault of a child.

Bexar County Sheriff Javier Salazar identified the deputy as 47-year-old Jose Nunez.

Salazar said Nunez is a 10 year veteran of BCSO who was assigned to the annex jail.

The victim is a 4-year-old girl. Salazar said investigators believe Nunez sexually assaulted the girl over some period of time.

"We know that it's been going on for several months," Salazar said. "We are not ruling out the fact that it could have been going back several years."

Salazar said the victim's mother is an undocumented immigrant and Nunez used that advantage to keep the mother from reporting the crime.

According to an arrest affidavit, Nunez threatened to have the woman deported after she confronted him.

She finally came forward Saturday evening when she took the girl to a local fire station.

"The details of the case are quite frankly heartbreaking, disturbing, disgusting and infuriating all at the same time, to be honest with you," Salazar said.

According to Salazar, Nunez will be charged with super aggravated sexual assault with a child and said he would not rule out any other victims.

Salazar urged anyone with more information to come forward to authorities. That extends to undocumented immigrants as well.

"Just like we are doing in this case, we are filling out paperwork with this witness in question to make sure that she's given protected status pending the outcome of this case," Salazar said.

"We will absolutely arrest you if you break the law and it doesn't matter if you wear a uniform, if you carry a badge, if you carry a gun. If you break the law, you are going to jail," Salazar said.