A Phoenix man was convicted of first-degree murder Wednesday in the 2011 death of a 10-year-old girl who was locked in a storage box in sweltering summer heat.

After deliberating for a day, a Maricopa County Superior Court jury also found John Michael Allen, 29, guilty of child abuse in the killing of Ame Deal.

Jurors now must determine whether the killing was especially cruel or heinous before moving onto the sentencing phase, which could include the death penalty.

Allen's 28-year-old wife Sammantha Allen, a cousin of Deal's, was convicted of murder in the girl's death in June. She now is on Arizona's death row.

Authorities said the couple forced Ame into the small, plastic box as punishment for stealing ice pops. They then went to sleep and the girl was found dead the next morning.

Defense attorney Robert Reinhardt had argued that John Allen, a father of four young children, did not intend for the girl to die and that the other adults in the home created the abusive environment.

Ame's death was the culmination of a shocking history of abuse at the hands of relatives who were charged with caring for her.

Authorities said the girl was forced to eat dog feces, crush aluminum cans barefoot, consume hot sauce and get in the storage box on other occasions. She also was kicked in the face, beaten with a wooden paddle and forcibly dunked after being thrown in a cold swimming pool, according to police investigators.

Adults at the home originally claimed Ame hid during a late-night game of hide-and-seek and wasn't found until hours later.

Three other relatives are in prison serving sentences for abusing Ame.

David Deal, who is listed as the girl's father on her birth certificate, is serving a 14-year sentence after pleading guilty to attempted child abuse.

Ame's legal guardian at the time of her death was her aunt, Cynthia Stoltzmann, who is serving a 24-year prison sentence for a child abuse conviction. Ame's grandmother, Judith Deal, is serving 10 years for child abuse.

Ame's mother left the family years earlier after suffering abuse from relatives and moved to Kansas without her daughter.