It's a known fact that the only thing humans cherish more than hoarding material wealth is complaining about a lack of said material items. This attribute has been explored in mythology, popular culture, and occasionally the back of a peanut-brittle wrapper, although unfortunately no one bothered to read it. Jasper was a whiny thief, meaning that not only did he revel in the pursuit of objects that weren't entirely his, but he also found solace in the acrimony that he would never have everything (a fact made true by some quantum law that I'm sure a man with a mustache dictated).
Whether he was swiping studying materials from scholars passersby or bumming around the maternity hatchery for surplus bits of placenta, Jasper took solace in his career choice, or lack thereof. See, thieving was nothing more than a whole lot of twiddling and only a fraction of actual action, the trick being knowing when to switch from twiddle to action and on whom to exact said guile. Again, it was common back-of-peanut-brittle-wrapper knowledge that being a woman, child, elder, or a combination of all three (a rare side-effect of drinking the local water) marked one with a rather large X in regards to twitchy pickpocket's fingers. Jasper, however, was the most supreme definition of a deviation from the norm. An enigma, you could say, but I'd prefer that you didn't. What was enigmatic was not only who he attempted to shake-down, but when and where, essentially violating all treatises set forth by the federation of thieves united (an assembly which had, in all seriousness, stolen its headquarters from some namby-pamby association of eclair bakers). He rejoiced at a chance to rappel down the wall of some sacred temple and rifle through a monk's robes while the friar beat his scalp against some dusty bricks, muttering an incantation damning theft and other sins as set forth by the Lord Joel. Joel being a rather silly name in our day, but having the mental effect of pouring ice-water over one's cojones back in who-knows-when. That's to say it was an intimidating thing to be named, and funnily enough the theologians of that particular temple preached peace, with the exception of a smattering of blood-wrenching purges to devolve any non-believers.
Besides rosaries and the canes of local blind-men, Jasper also found a particular interest in the acquirement of Watch-Guard armor and ammo, taking a special interest in the situation of having a Guardsmen turn on him with crossbow firmly gripped in hand, firing, cursing, and then realizing that polluted air is not as fatal of a projectile as some environmentalists think. That is, except for the instances in which he had left behind one or two arrows, in which case he put to use the most effective weapon in any thief's arsenal: sprinting. In fact, the sign of a laudable thief is having more people know the look of the back of your head than your scraggly face.