PHILADELPHIA - A former SEPTA Revenue Agent accused of slugging a rider at Frankford Transportation Center in late September has been fired by SEPTA and is now facing assault charges.Byron McCaskill, who was let go by SEPTA after he was allegedly captured on video punching out a rider, has been charged with simple assault, official oppression, harassment and disorderly conduct, according to court documents.Surveillance video obtained by FOX 29 in late September allegedly shows McCaskill take two jabs at the victim, striking him at least once in the face, in the concourse of the busy SEPTA stop located on the 5200 block of Frankford Avenue.