The resent change to requiring Salt to destroy a Field got me thinking, if this is a "crafting MMO" could or should other crimes become item based too? Requiring the expenditure of a crafted or foraged item for every crime is certainly a big obstacle to committing casual crimes simply because you won't typically have the item with you, but if the items are cheap enough it's only a minor challenge to bring the items when raiding, more concerted attacks/sieges should of course require more items and entail a higher expense, groups are already expending huge sums on things like offensive town claims so this would really just be an attempt to make these expenditures more interesting then stuffing heaping handfuls of silver into a bell.
Crime items could have some tiers that can counter the tiers of the defenders base structures, for example a different tier of attack item to overcome each wall tier with the cannon we've been teased with obviously being the counter item for the newest wall type. Having the crafting capability to make these tiers of attack items will give high tier crafters a bit more of a direct sense of participation in conflict and a higher value vs the current paradigm of simply fueling the humor gain of combatants. With large expenditures fueling conflict we would see economics/crafting gets to fuel war which complements the devs plans for stalls which are said to be something to fight over, so the two come full circle and feed off each other.
Trespassing as it exists now would be very hard to itemize, I've suggested trespassing be redefined as a wall-passing maneuver and that would presumably be done with ropes and metal grappling hooks at higher level. Things like lock-picks or skeleton keys might be used to overcome locks, obviously these need to be properly designed to support scouting and narrowly targeted stealing without being methods to level a base.
Larceny is fairly simple matter to itemize, a larceny item is simply right-clicked onto the item you wish to steal and the stolen goods are now on the mouse to be put in your inventory. The larceny item might break or might be left behind in the place of the stolen item and be reusable to encourage some tit-for-tat 'stealing back', better tier larceny items break more often and thus leave less evidence.
Assault/Battery is a bit tricky to handle with an item, as combat can involve a lot of people any item that's used should give the player a time period in which they can initiate combat with any player rather then requiring an item per person, something like a Savage Charm equipped to the face slot could work.
Murder on the other hand is a fairly easy crime to itemize because of the explicitness of Killing Blow, obviously the item would be some big bloody knife, scalping could use the same knife.
Devs have mention structure vandalism being replaced with 'Arson' in which will damage structures over a long period of time and be extinguishable by the defenders, this would be a very simple thing to itemize with some kind of special torch and is most consistent with the existing field/salt changes.