He was born from unknown parents. I think that he ,aybe was raised in an orphanage. After that perhaps he was a thief or something like that. Poor, hungry or so. Could be the reason für his sentencing. Only a theory.

Edit: @Sowilo

that supports my theory. He convinced me too but I was sure, that the Dagoth today isn't still the normal friend he was once and that his way now would be the wrong way ;9 So I had to kill him for saving the country and the people. But I had a very bad feeling about this.