Garrett is a talented inventor and engineer — he has built and assembled a folding bow and various arrows for it, repaired the ancient mechanism in the Clock Tower; Garrett's work suit and equipment are undoubtedly also of his own invention; he easily solves the difficult and sometimes deadly puzzles that he faces while committing theft.
The master thief is also a good judge of people, so by breaking into their homes, reading letters and eavesdropping on conversations.