Prefect

I used to work as the District Attorney for Gotham, where I used to live. One day, these corrupt cops kidnapped me. They put me in a warehouse filled with oil. Also, they put a phone rigged to explosives in there. I could talk to my fiancee, who was in another warehouse with oil. I tried to get free, but ended up soaking half my face in oil. They were supposed to save her...but he came into my warehouse and saved me instead. Then, when we both were out of the warehouse it exploded. Rachel...she died. A spark caught my face on fire. At the hospital, they said they could put skin grafts on my face to fix it up. I didn't want them to. My face stayed the way it was.

...and that's how I got my scar.