There are really two possible explanations:
For the inevitable assassin character I play, it will because the strange little Bosmer is not alright in the head. The Nords never really liked the guy in the first place, I mean he's pale as all get out, and never talks to anybody ever. They found him one night in a noble woman's house in the fettle position in a pool of blood, blabbering incoherently about the divine purpose the Night Mother has for him. Yeah...people were freaked out.
For the mage/warrior/combination of the two I play: An skilled (magic)/athletic (warrior) youth who became a respected protector of his village, and thus inspired much jealousy in his peers. One night, a band of thugs decided to gang rape a girl. That girl turned out to be our hero's sister. None of them survived. The guards were called in regardless.