Nineteen-year-old Silvonus Shannon, 18-year-old Eugene Riley and 16-year-old Eric Carson have been indicted on murder charges and mob action for their alleged roles in the Sept. 24 beating, which was caught on a amateur video tape.
The graphic footage shows the 16-year-old Christian Fenger Academy High School student being hit with boards, kicked and punched as he lay on a sidewalk.
Judge Nicholas Ford accepted the pleas and set a Dec. 9 status hearing.
A fourth teen has been charged as a juvenile with murder. His name has not been released.