According to officials, Robinson called 911 on July 18, 2012 reporting that he'd arrived at his north Phoenix apartment to find it on fire, and was unsure if his girlfriend was still inside.
Firefighters entered the home and found 21-year-old Shaniqua Hall, who was 9 months pregnant at the time, bound with duct tape, a rag shoved down her throat, and handcuffed inside a bedroom.
Investigators found evidence that the fire had been intentionally set and an accelerant used.
During the trial's penalty phase, jurors found seven aggravating factors, leaving Robinson eligible for the death penalty.
“The callous and inhumane killing of his girlfriend and their unborn child is the worst example of a man utterly failing those who counted on him for love and support," said Maricopa County Attorney Bill Montgomery. "The jury’s verdict accurately and properly imposes the death penalty as a just and proportionate punishment for these despicable crimes.”