MILWAUKEE -

Authorities say a 10-year-old girl who was shot on a Milwaukee playground in May has died.

The Milwaukee County Medical Examiner's Office says in a statement that Sierra Guyton was pronounced dead at Children's Hospital at 1:35 a.m. Sunday. The office says it won't release further information and that police have put a non-disclosure order on the case.

Sierra was playing with her 12-year-old sister when she was shot in the head May 21.

Two suspects have been charged. According to the criminal complaint, 18-year-old Sylvester Lewis told police he knew children were in the area when he fired opened fire in retaliation after a bullet whizzed by his ear during a confrontation with other men. He was charged with first-degree reckless injury and two other felonies.