Tallahassee police arrested 15-year-old Anthony Rivers III on Sunday in the mass shooting near Florida A&M University. State Attorney Jack Campbell says he will prosecute Rivers as an adult. That choice moves the case out of juvenile court and into adult court, where the stakes for a teen defendant are much higher for families watching the case.

Rivers is charged with 11 counts of attempted second-degree murder and possession of a firearm by a delinquent, police said. Those charges are accusations. At a Monday detention hearing, Judge Andrew Sheeran ordered him held in secure detention. The judge also barred contact with victims and witnesses and banned social media use. Phone calls from detention, except with his lawyer, must be monitored.

The shooting happened near Perry and Manatee streets after a fight, Tallahassee police said. Twelve people were hurt. Eleven were shot, and one person was hurt while fleeing. Six of the injured were juveniles, including an 11-year-old. Police said none of the victims appear to have been the intended targets. Detectives believe the dispute involved people known to one another. More arrests are possible. The arrest affidavit was sealed at the police department's request.

The violence came during FAMU's homecoming weekend near Bragg Memorial Stadium. Rivers' arraignment had been set for November 16, but Campbell expects that date to change as the case moves to adult court. Chief Lawrence Revell said the arrest is a step forward and that the investigation continues.

What we know: Rivers, 15, faces 11 attempted second-degree murder counts and a firearms charge. Campbell will seek adult prosecution. Sheeran ordered secure detention.
What we don't: A full public account of who fired and why, and whether others will face charges.