What happened to Bakari's father in February of 1968 as noted in the memoir, My Vanishing Country?

In February of 1968, Bakari's father, Cleveland Sellers, led a peaceful anti-segregation demonstration in Orangeburg, South Carolina. Police officers attacked the protesters with lethal force, killing three and injuring 28. Despite evidence that the attack was planned, and that the police were specifically attempting to kill Cleveland, no police officers were convicted of crimes. Meanwhile, Cleveland was falsely convicted of attempting to incite violence.