A Cobb County judge has ruled that a 12-year-old Florida boy will remain in jail in the death of his 5-week-old cousin.

Juvenile Court Judge A. Gregory Poole ordered the boy, who is from Tampa, held until the Sept. 8 trial at a hearing on Friday. The boy entered a not guilty plea.

Police say a 22-year-old Kennesaw woman left her daughter in the car with the boy Saturday while she went into a store, and called police when she came back and found the baby was not breathing.

The baby was pronounced dead at a hospital Sunday night. Police say an autopsy showed the baby died of blunt force trauma.

The boy is being held at the Cobb County youth detention center on charges of murder and cruelty to children.

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