The Milwaukee DA's Office has charged Sylvester Lewis with three felonies, while 10-year-old Sierra Guyton remains hospitalized.
Police say the girl was playing outside at Clarke Street School last Wednesday evening, when people began firing shots across the playground, and a bullet struck her in the head.
In the criminal complaint filed against him, Lewis says he fired a gun toward the playground, because a man hanging out had shot at Lewis.
If convicted of the three felonies, the teen could be imprisoned for more than 47 years.
One charge against him is the reckless injury of Sierra Guyton. A second is recklessly endangering the Safety of Kiara Guyton, and the third is possession of a firearm by a felon.
According to Milwaukee Police Chief Edward Flynn, the 18-year-old has been arrested 15 other times. He was convicted and sentenced for burglary in early 2013, but a judge stayed the sentence.