If you call someone a cold-blooded killer in public, you'd better have the facts on your side.

That's our free, untrained legal advice for Rep. John Murtha, D-Pa., who said precisely that about a handful of Marines once accused of killing civilians in Haditha, Iraq.

Seven of the eight Marines initially charged in connection with the alleged incident have been exonerated.

There were four charged with participating in the alleged massacre, and four charged with failing to properly investigate it. Lt. Col. Jeffrey Chessani was charged with failing to properly investigate it, but a military judge this week dismissed the case.

Now, Chessani's lawyer says they are considering a lawsuit against Congressman Murtha.

That would be rich, indeed.

Murtha, who as a former Marine should have known better than to go off half-cocked, was as strident as possible in condemning our troops before they ever went to trial or were even fully investigated.

In May 2006, Murtha said the Marines "killed innocent civilians in cold blood."

We don't know what happened in Haditha. We don't know if Chessani would have a case against Murtha in a lawsuit. But one way or another, there ought to be accountability.

Were the allegations of atrocities ever true, or did the enemy's propaganda machine and penchant for lying dupe Murtha and the mainstream media?

With the criminal cases against the eight Marines crumbling, perhaps a lawsuit is the only way to get to the truth.

If the Marines were targeted as scapegoats to fulfill the scenario laid out by Murtha and the media, then no amount of apologies will suffice.

If some atrocity did happen, then why are the cases collapsing under their own weight?

And what obligation does the military and the public have to stand behind our troops when we put them in harm's way against an enemy that hides behind women and children?

Moreover, shouldn't our elected officials stand behind our troops in wartime until it's proven beyond a reasonable doubt that they weren't worthy of it?

You call someone a killer -- even in wartime -- you better be sure of it.