Should Americans be tried in Iraqi courts if they commit heinous crimes?

I've recently read about the 2006 Mahmoudiya incident, where Army personnel plotted a murder and of an Iraqi girl and her family. I've never been so upset and appalled in my life. I think that Americans that commit gross crimes against humanity in other countries should be tried in the courts of said countries. Meting out 100 year sentences, with possibility of parole in as little as 10 years is hardly justice for the survivors. I dont' consider myself to be a total pacifist, but at the same time I think that when such crimes are commited against innocent civilians, they should face the laws of the land - whatever they may be. There is no excuse for premedidated murder and disregard for human life - such as the killing of a five year old by shooting them in the head.