Step 1: Post a nice 500 gold bounty on the priest. Bounties are anonymous.
Step 2: Let an infil from another realm know where the priest is--you certainly wouldn't want an infil from your own realm to stab them.
Step 3: make sure that all of your realms' nobles are out of the region when the stabbing occurs, for deniability.
Which won't come even remotely close to stopping us from blaming whoever we want. Could be the realm the infiltrator is from. Could be the realm that let a priest get assaulted within their borders. Or maybe we'll let it slide. It all depends on what our particular goals are at any given time, not to mention what's going on in the halls of the Church.
