DNA checks to identify attack victims 'could take two years or more'

Identifying the victims of Tuesday's terrorist attacks in the United States will require painstaking DNA checks that could take years.

Some of the dead may never be conclusively identified because they will have been burnt almost to ash in the fires that followed the jet crashes, according to Peter Vanezis, professor of forensic medicine and science at Glasgow University.

For those anxiously awaiting news of their loved ones, the delay may add to their grief. But it is unavoidable. The sites of the crashes are crime scenes, with every piece of rubble being sifted for clues to the identity and actions of the hijackers; identifying victims will be a long haul.

"We are talking about a long time," Professor Vanezis said yesterday. "One year, two years. Maybe more." That is the bleakest of prospects for families who will then have to ponder the appropriate form of burial for loved ones who have been brutally torn apart by the towers they hoped would protect them. Cremation or burial may feel like a cruel repetition of the fate that overtook them, and may be complicated by the difficulty of knowing when the recovery is complete as the search of the disaster sites continues, probably for months.

Yet that thoroughness should also mean that the families and friends of those who have disappeared will get the small consolation of confirmation through the most modern forensic methods: DNA profiling, which can identify someone from a lone tooth or a charred bone.

"It is a nightmare," said Professor Vanezis of the task of tallying the names and details of thousands of people reported missing with the remains now being unearthed in the grim ruins.

"But we have to bear in mind that we will have many victims in different conditions, a whole spectrum. Some will have been injured by masonry but not mutilated, and thus identifiable. Some might be identified from the documents on the body, or hair, or eyes, or clothing. Others may not be recognisable at all on the surface. Others," he added, "will have been virtually vaporised in the fire."

He said that "from our point of view, working in the mortuary, we have to assume that people in an aeroplane have been traumatised in a physical way, other than by the crash itself.

"We would need to be looking, for example, to see if they had stab wounds, gunshot wounds. We would need to identify the people who were the terrorists, who were the key players on the particular aeroplane. To do that helps in the reconstruction of what happened."

All those who have reported friends or relatives as missing are being asked to complete detailed seven-page descriptions of the person. The data from those will be matched against the details which emerge.

The grisly task of identification will then fall on DNA profiling. "We can extract useful DNA even from bone, or the fleshy pulp of a tooth," Professor Vanezis said. "Bone can survive fire. We can process the DNA of relatives of potential victims in our own laboratories from a simple mouth swab; we can then send the profile over to the US, which simplifies the task for them."

But matching those profiles against data extracted from the remains dug out of the rubble will be a long, slow task requiring diligence and patience – both by the scientists and the people waiting for some closure on events.