I am a 29 yr old Canadian, with no Criminal Record. Recently I was charged with "Assault Causing Bodily Harm". Here are the details.

I was driving in the "bad" area of town, when a girl approached my car. She was sitting on a bench on a side street near a main route. She asked if she could "warm up' in my car. She offered me "sexual favors" for a price she suggested. After thinking about it for a brief period of time, I accepted a "favor". Money was exchanged prior to the act, and upon completion, I dropped her off at the address she requested. We left on good terms.

After a couple of hours of visiting a friend nearby, I drove back down the same main road, and noticed the same woman waving at my car. Mistakingly, I pulled onto the side street, and asked what was up, since he had left on good terms. She asked to warm up in my car again. I refused, saying that I was on my way home, and apologized. She reacted by punching my car twice, and breaking my passenger door handle.

Caught completetly off-guard, I did a U-turn, and asked from across the road why she had hit my car for? She stormed over to my vehicle, and said that she wanted more money, claiming I had "mistakenly" given her less money than was agreed upon. I assured her that I did not, and I did not have any cash on me. She proceeded to say that if I did not give her $20 right away, she would "track my plate #, and would get "people to f**k me up. I began to panic, and said I was sorry but I did not have any money on me.

She got closer to the drivers side, a foot away from my face, and yelled that she wanted money. She also advised me "not to drive, or I would regret it". I panicked. I perceived these two comments as immediate threats, and was afraid that she might have a weapon (knife, etc) on her person. I ended up using force, and making contact with her face. She retreated, grabbing her face, and hovering on the ground. In fear, I drove off, but was apprehended by the vice squad one minute later, who arrested me, and charged me with the offense.

I know what I did was morally wrong, and not very smart (getting involved in the sex-trade), but what kind of defense would this make? I regret using any kind of force (in the process, I gave her a bloody nose), but I was not calm, and in some amount of fear. I would have just gave her the $20 to avoid trouble, but unfortunately i only had some loose change. Now I have to go to court, and fight this charge. Do I have a chance of winning the case on the grounds of self-defense, or reducing it to a lesser charge? Please help me!