If I'm caught, even if I can get away, I will reload the game and do it again - till I get it right
That is what I'm doing with my current assassin character too.
She was given the job of assassinating a certain mine owner. She did the job in one blow while the target was eating on her front porch. The nearest guard was all the way across the bay. They drew their bows, but my character had plenty of time to get away. I reloaded anyway. I am roleplaying a character who is swift, silent, efficient and professional. A messy kill is not the way she does things.
The second time she waited in the target's house. We waited for hours. It was literally about 40 real time minutes.
Both of us were waiting - me in real time, my character in game time - and we were both getting a little anxious to get this over with. Eventually the target entered her house, my character killed her with one stroke, sheathed her blade and left town like a shadow. Calling cards are for amateurs, in her view.