The reports provided by the counter detailed the location of the merchant's house and his shops, also brief information about his family and his normal itinerary. Based on these basic reports, Amon started to follow and spy on the merchant in secret.
Scouting and trailing someone was child's play for him. With the addition of him being in the body of a kid, it made the job even easier. People tended to not suspect children. Amon brought many different attires and hats that he changed regularly while trailing the merchant. After all, if the bodyguards kept on seeing the same kid, they would still get suspicious.