The father was in his bed with his two daughters when he began stabbing the 11-year-old girl.
Action 4 News learned that family members were woken up to the girl screaming and called 911.
It happened Tuesday morning at about 7 at a house on the 5200 block of J M Martinez in Rio Grande City.
Starr County Deputies said the girl was stabbed a total of 21 times in her arms and legs before her father turned the knife on himself.
He stabbed himself twice in the neck.
The man is going through a divorce from his wife, and currently lives with his parents.
This happens to be his week to have custody of his two children.
The sheriff TMs office is not releasing the suspect TMs identity because he has not been formally charged with a crime.
Investigators said he is taking medication to deal with the divorce, but it TMs unclear what medications he is taking.
Authorities said they TMve been called to this house before for domestic violence.