Three teens and one man accused of brutally beating to death a 15-year-old Donaldsonville High student in August 2014 while high on synthetic marijuana were arraigned Monday and pleaded not guilty to murder charges, prosecutors said.

Assistant District Attorney Shawn Bush confirmed the initial pleas Monday of Marcus Ester, 21; Tyrell Williams, 18; Kahlil Howard, 17; and Kaglin Green, 16, all of Donaldsonville, on single counts of second-degree murder.

The four were indicted Aug. 6 after their arrest in June. Ascension Parish sheriff’s deputies claimed at the time of their arrest that the four suspects beat Brandon Augusta with driftwood and pieces of concrete after an argument.

Augusta was reported missing less than a day after being seen with a group of friends Aug. 9, 2014. His badly beaten body was found four days later on the Mississippi River levee, but it took investigators 10 months to make arrests.

In mid-June, a state district judge ruled the youngest defendants, Green and Howard, could be tried as adults in the slaying.

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