Law & Order: Criminal Intent

I originally wondered if the character played by Vincent D'Onofrio was written that way or did he create his characters personality. I have since watched Daredevil and see that it is D'Onofrio's acting skills that create his odd character roles. I believe that you can compare his character in this to Dustin Hoffman in Rainman & Billy Bob Thorton in Slingblade. 10 years was not enough for this show but I loved every episode and now find myself watching anything he is in.