Sugar Land police arrived at the home in the 5200 block Weatherstone Circle around 10:40 a.m. after the father arrived home and saw blood throughout the house.
The child's mother was identified as 36-year-old Ritika Rohatgi Agrawal. She has been charged with murder.
Agrawal was said to have injuries when authorities arrived on scene.
The man saw Agrawal wandering around the home with self-inflicted cut wounds to her neck and wrists, authorities say.
Police found the couple's 4-year-old son upstairs with his throat slit.
Investigation was underway Saturday afternoon to determine what exactly happened.
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