While I agree that an investigation is needed before anyone can say that war crimes have been committed, I also would say that an investigaion is needed before anyone can say that war crimes have not been committed.

If the Israelis had any desire to systemically or indiscriminately kill innocent people, it would be much more efficient to simply bomb the Palestinians

I disagree with this supposition. Whether or not the Israeli military are guilty of war crimes, one thing they certainly aren't is stupid. If they were going systematically or indiscriminately kill innocent people, they would do pretty much what has been done: they would prevent any outside observers from being in the area while the military operation was taking place, and then they would remove and bury any bodies themselves with no independent observers present. This has already been done. And we know that the Israeli Supreme Court authorized the removal and burial of the bodies by the Israeli military.

If, as a result of these practices, Israel finds itself dealing with the perception that it may have committed war crimes, they really have themselves to thank for that.

I don't find it terribly difficult to accept the idea that the Israeli military could commit war crimes for two reasons...

Someone I know who has an extensive military and law enforcement background worked closely with the Israeli military and police forces as a consultant during the Gulf War. A year or so ago, he told me some things about the Israeli military's standard operating procedure. This person has the utmost admiration for the Israeli military, so he wasn't saying anything in a critical sort of way. He actually endorses these practices. However, they do involve some highly questionable practices according to international law.

And I just can't get the image out of my mind that I saw of a man sitting on his living room floor looking bewildered, while the bodies of his brother and sister-in-law were in the process of decomposing on the floor next to him. They were killed by the Israeli military, and because of the Israeli military, the man was not able to remove these loved ones from his living room for several days. I don't think this was in Jenin. I think it was in one of the other places that the Israeli military has been conducting incursions.

And then there are the reports by independent observers of Israeli military forces indiscriminately killing anyone they saw in the street, such as a woman who was trying to get to a clinic to have a wounded arm looked after (not in Janin), and the firefighters who were trying to put out a fire behind the the besieged church in Bethlehem (and many others).

No matter how you slice it, these things don't look good for Israel.