THURSDAY, 4:15PM ET UPDATE: Nikolas Cruz withdrew his not guilty plea Thursday and instead chose to "stand mute," according to a court motion.
The Cox Media Group National Content Desk contributed to this report.
A grand jury in Broward County has formally indicted Nikolas Cruz in the Feb. 14 massacre at Marjory Stoneman Douglas High, the county's state attorney announced Wednesday.
>> Read more trending news
The panel charged the 19-year-old with 17 counts of premeditated first-degree murder and 17 counts of attempted first-degree murder in the mass shooting at the Parkland high school that left 14 students and three adults dead.