Richardson is accused of torturing, sexually assaulting and beating 4-year-old Teghan Skiba in July 2010.
Helen Parish Creech testified that she was afraid of her grandson, and that he had a temper.
"Jonathan got angry with me more when I would ask him a personal question about his personal life," said Creech. "He would have more flare-ups when he was tired or sleepy."
Creech also described the black eye she once saw on Teghan. She said the girl's mother was home at the time and told her that the little girl had fallen.
She also talked about going out to the shed where they all lived without water or a bathroom. However, she didn't report it because she didn't want authorities to take the child.
Richardson's defense claims Skiba's death was an accident.
If convicted, Richardson could face the death penalty.