Jasmine Gabriella Olivas and Segundo M. Ramirez were arrested around 2 PM on Wednesday.
Odessa Police say that Olivas, 20, and Ramirez, 23, seriously injured Omar Frias Jr. earlier this month.
Olivas is the child's mother, while Ramirez is the child's stepfather.
Police say that family members brought Frias to Medical Center Hospital around 3 PM on on January 10th, after the child was found to be unresponsive.
Frias, 3, was treated at the hospital and then taken to Cook's Children's Hospital in Fort Worth.
However, officers say that Frias died at Cooks Children's Hospital on January 11th.
The Tarrant County Medical Examiner's Office performed an autopsy on the child's body on January 11th.
The autopsy determined that Frias died from blunt force trauma to the abdomen.
The Tarrant County Medical Examiner's Office later ruled Frias' death as a homicide, and Odessa Police opened up an investigation.
The investigation culminated in arrest warrants for Olivas and Ramirez.
Now, Olivas and Ramirez are each charged with capital murder.
As of Wednesday evening, both Olivas and Ramirez were being held in the Ector County Law Enforcement Center without a posted bond.