Louisiana ? A black teenager whose prosecution in the beating of a white classmate led to one of the largest civil rights protests in years pleaded guilty Monday to a battery charge.

Mychal Bell, 17, originally was charged as an adult with attempted murder in the beating of Justin Barker in December 2006. That charge was reduced before a jury convicted him in June of aggravated second-degree battery. An appeals court threw that verdict out in September and ordered Bell retried as a juvenile.

Under his deal, Bell pleaded guilty to a juvenile charge of second-degree battery in return for an 18-month sentence, with credit for 10 months he already has served. Bell had faced being placed in a juvenile facility until his 21st birthday.

Bell also must pay court costs plus $935 to Barker’s family, testify should his co-defendants in the Barker attack stand trial, undergo counseling and be reintegrated into the school system, his lawyers said.