Cops were called after the girls injuries were found during a trip to the hospital.At first the little girl told her mom that a fall on bars at school was the cause for injuries that required a hospital visit. But after talking with Wenatchee cops, the eight-year-old changed her story: her 13-year-old stepbrother, she said, forced himself on her in his bedroom.Prosecutors have now charged the 13-year-old with first-degree rape of a child. Court documents say that the boy told police he’d had sexual contact with the girl two other times in the past four months.The charges were brought in Chelan County Juvenile Court. There’s no word yet on how what the boy’s punishment might be.