"We're going to drag every single, two-star and full-bird colonel and general into this thing, " said Kevin McDermott, a California-based lawyer representing Captain Lucas McConnell, the commander of Kilo Company which carried out the Haditha killings.

In all, 24 Iraqis, including six children, several women and an old man in a wheelchair, were killed in Haditha as the marines responded to the death of a colleague in a roadside bombing in November 2005.

Only five of the dead Iraqis have been identified as militants.

Four marines under McConnell's command were charged with unpremeditated murder last week, facing life imprisonment if their military trials go ahead and they are convicted.

The man who headed up a series of deadly house-to-house raids that day, Staff Sergeant Frank Wuterich, is personally accused of murdering 12 people.

Many critics of the military brass have argued that the Haditha incident might have been written off as business as usual were it not for graphic Iraqi documentation of the massacre that made the cover of Timemagazine last spring. The military initially claimed, erroneously, that the roadside bomb killed 15 of the Iraqis, and nominated Wuterich for a medal for bravery.

Responding to the charges against his client, McDermott said the top brass was well aware of what happened, but condemned it only after it became glaringly public.

"A lot of lieutenant colonels and colonels and generals knew what happened that day, and nobody said, 'Let's do a thorough investigation of what happened, '" he charged. "By the end of the day, [my client's] superiors recognised the situation was so significant that they brought in air support.

"There were Harriers dropping 500lb bombs on buildings.

If they're dropping 500-lb bombs without knocking on the door first, how can you argue the troops on the ground did anything wrong?"

In Iraq, meanwhile, angry residents of Haditha believe the only way to achieve just redress for the massacre would be to have them tried locally.