John Allen has been sentenced to death in the 2011 murder of 10-year-old Ame Deal.
A jury found Allen guilty of first-degree murder, as well as three counts of child abuse and conspiracy to commit child abuse on Nov. 8.
Allen's wife, Sammantha Allen, was found guilty of first-degree murder in June and was sentenced to death in August.
According to the Arizona Department of Corrections, Sammantha and John Allen are the first couple in the state to be sentenced to death row.
"I want to say that I'm sorry," said a tearful John Allen moments after he was sentenced to death. "What happened was an accident. I'm an idiot. I'm a jerk. It was an accident."
Deal died after John and Sammantha, Deal’s cousin, locked her in a plastic box overnight during the summer as punishment for taking a popsicle without asking. The 10-year-old died of suffocation and heat.
"This was one of the most unnecessary deaths of a child I've ever seen," said Judge Erin Otis.
Allen's family was emotional as they left Maricopa County Superior Court. His sister told the media the disturbing history of abuse toward Deal started long before her brother was in the picture.
"Just for my brother to be in this situation, it saddens my heart. It breaks my heart that he didn't say anything when he could've," Allen's sister said. "He made a mistake and he's going to pay for it with his life. And I'm gonna miss him."
During Sammantha’s trial, investigators testified the house was also filthy, covered with trash and debris.
Other family members have been sentenced to time in jail for Deal’s death.
Deal's father, David Deal, previously pleaded guilty to attempted child abuse. Her grandmother, Judith Deal, was also sentenced to jail time for her role in the abuse. And Deal's aunt Cynthia Stoltzmann was sentenced to 25 years in jail for attempted child abuse.