Lindsay Groce, 27, died of hypothermia with paradoxical undressing. Her 13-month-old, Hailey Gardner, died of hypothermia.
Groce's and Gardner's unclothed bodies were found together in January in a field near Altamesa Boulevard and Bryant Irving Road. Groce's crashed car was discovered in a tree in the same field.
Groce's family members said in January that they believed she and her baby died after they became injured and stranded.
"A nurse called me today saying that they've run into cases where someone gets so into hypothermia, they get distraught and they can't figure out what they're doing," Groce's uncle, Ewin, Grace, told FOX 4 in January. "They begin to take their clothes off because it feels like they're burning rather than freezing."
The low temperature the night that Groce went missing was below freezing.