Roger Torres, 21, is charged with aggravated sexual assault of a child after the victim's mother discovered a video of the suspect performing sexual acts with her 12-year-old daughter.
An arrest affidavit stated the girl was asleep on Christmas Eve when she awoke and noticed Torres walking quickly out of the room.
The girl told her mother about the incident and the girl's mother returned to the home and found a video camera, but could not see what was recorded, the affidavit stated.
The mother told San Antonio police detectives she took out the memory card and played it on another laptop.
The affidavit stated the mother saw Torres performing sexual acts on her daughter as she slept.
Torres was confronted about the video and according to the affidavit, he admitted it was him in the video and he was intoxicated at the time.
A warrant was issued for Torres' arrest and he was taken into custody last Friday by San Antonio police.