Before his release, civil rights leader Al Sharpton and other supporters stood at the courthouse, where tens of thousands of protesters gathered last week.
Bail was set at $45,000 for Bell, according to a spokeswoman for a local bail bonding service. Court officials would not release information on Bell's case since it is now a juvenile court matter.
District Attorney Reed Walters credited the prayers of people in this small central Louisiana town with averting a "disaster" during the demonstration. Some critics of Walters considered that a slap against the peaceful marchers.
Walters's decision to abandon adult charges means that Bell, who had faced a maximum of 15 years in prison on his aggravated second-degree battery conviction last month, cannot get anything close to that sentence.
The conviction in adult court was thrown out this month by the state Third Circuit Court of Appeal, which said Bell should not have been tried as an adult on that particular charge.
Walters had said he would appeal that decision. Yesterday, he said he still believes there was legal merit to trying Bell as an adult, but decided it was in the best interest of the victim, Justin Barker, and his family to let the juvenile court handle the case.
"They are on board with what I decided," Walters said at a news conference.
Walters's announcement had been expected. Governor Kathleen Blanco, with Sharpton and Martin Luther King III at her side, announced Wednesday that Walters had agreed to move the case to juvenile court.
Walters said Bell faces juvenile court charges of aggravated second-degree battery and conspiracy to commit that crime.
David Utter, director of the Louisiana Juvenile Justice Project, said conviction on those counts could keep Bell locked up until he turns 21.
Bell is among six black Jena High School students arrested in December after a beating that left Barker unconscious and bloody, though the victim was able to attend a school function later the same day.
Four of the defendants were 17 at the time, and legally adults under Louisiana law.