Police said the teen and another male went into Diamond Custom Jewelry, 6065 S. Highland Drive, on March 13, 2012, wielding guns.
Employees told Unified police that the bigger man detained employees while the smaller male proceeded to smash the glass cases and take the jewelry.
During the robbery, one employee suffered injuries to her back and hip that required a hip replacement. Another received a cut above her eyebrow that required stitches, suffered a broken tooth that required surgery, a broken left wrist, head trauma, whiplash and bruised ribs as a result of the robbery, according to charging documents filed in Third District Juvenile Court.
The two males then fled with about $93,000 in jewelry and caused about $2,000 in damage, charging documents show.
Police recovered blood from one of the smashed glass cases. CODIS, the FBI Combined DNA Index System, matched the blood on the broken cases to the teen, who was a previous juvenile offender.