A similar entry appears in the Wheel of Time Companion confirming the information available in the main story arc.
Author: Atarah al'Norahn
He and Nad, the other man in their employ, look similar enough to be brothers. Both have black hair, beady eyes, plenty of scars, and more muscles than any three men could need. In Falion's opinion, they have enough brains to carry out simple orders.
After Falion and Ispan finish questioning Callie, one of the Kin, about the cache of angreal, sa'angreal and ter'angreal, Falion tells Arnin and Nad to dispose of Callie's body in an alley, and to slit her throat so that it looks like a robbery; she also tells them that they can keep the coins in Callie's purse. Arnin tries to tell her that no one will believe Callie was robbed, but Falion orders him to do as he is told. She channels to haul him off his feet and slam him against a wall, after which he does not give any more objections.
Later, Noal Charin sees Arnin and Nad pushing a barrow piled high with soiled straw and muck, and wonders what they are doing; he thinks to himself that Arnin and Nad aren't the type of men to be mucking out stables. Likely, they are carrying out Falion's orders.
(Reference: A Crown of Swords, Chapter 17)