A third suspect has been arrested in the vicious beating of a homeless man outside an Olney Sunoco station.

Police said today that Kaisha Duggins, 23, was among those in the group that attacked Robert Barnes, 51, with a hammer, a piece of wood, Mace, and their fists on April 7.

The brutal assault, which left Barnes in a medically-induced coma with catastrophic brain injuries, was allegedly triggered when Aleathea Gilliard's son told her that Barnes had hit him at the gas station.

Police said surveillance footage shows that Barnes never touched the boy.

Gilliard, 34, and another person who attacked Barnes, Shamira Joachim, 24, were arrested hours after the attack. Like Duggins, they all are all facing aggravated assault and attempted murder charges, police said.