Sean McCallum was Chief of the 1875th Federation Police Special Ops Command. He displayed absolute obedience to orders given by headquarters. A fundamentally stubborn man, yet thoughtful in his consideration for his subordinates - especially Jan Sauer. Perhaps it is because he worked for Jan's father, he displays an understanding and compassion like that of a father figure. Ernest Luis was appointed Chief of the 1875th Special Ops Command in place of Sean McCallum, shortly after McCallum was arrested in a plot devised by Dmitri Yuriev in 4667.