User blog comment:Prolietor Dominus/Skyrim info from PC Gamer/@comment-2053932-20111004141201/@comment-2.122.243.234-20111004153408

perhaps for the same reason you would kill the thief: equipment or money. I suspect that the guard will pay more and give more (although probably less rare) equipment. As for me, a high elf student of the College of Winterhold doesn't seem like a good canditate for either (not even the imperial battlemages, if they are still active)