Police say identifying all the victims of the Christchurch earthquake could take weeks, and possibly months.
Over 240 DVI staff are involved, including teams from Australia, UK, Japan, China, Thailand, Korea, Singapore and Israel.
Superintendent Sam Hoyle says the DVI teams continue to work carefully through the complex identification process but it won't be done overnight.
"We are acutely aware that families want their loved ones returned, particularly our guests from overseas, and our teams are working flat out to achieve this.
"However international experience from events such as the Boxing Day Tsunami and the Victoria bush fires has shown it can be months before all identities are confirmed.
"In exceptional cases it has taken years to identify all the victims of mass casualty events.
"This is painstaking, exacting work and the reality is very different from how it looks in television programmes such as CSI.
"You don't get DNA matches in seconds at the push of a button - it takes time.
"We are following international best practice standards and have some of the most experienced DVI specialists in the world working with us.
"The focus is to make accurate identifications. We are not going to rush this process and risk causing further pain to grieving families by making a mistake.
"If we make a mistake we create uncertainty and doubt for everyone.
"We can't make it better for the families but we can certainly make it worse for them if we get it wrong.
"We ask for your patience and understanding while our large team continues to work through this difficult and complex job."
Editors: Further information on the DVI process can be found below.
Police media line in Christchurch: 0274 320 960
There are five stages in the DVI process, work on all stages will be carried out concurrently.
The five stages are:
Postmortem phases: collecting detail from the recovered body
Phase 1: Scene
• Police DVI support USAR efforts at the various scenes.
• Any human remains are examined and documented in situ, then taken to a temporary holding area.
Phase 2: Mortuary
• Body (or human remains) is examined in detail by a pathologist, forensic dentist, fingerprint officer and Police DVI team
• Coroner is advised and may choose to attend
• Personal effects (such as jewelry, clothing) are photographed in situ, then collected, examined, cleaned, rephotographed and secured.
Antemortem phase: information about missing person is brought in from outside
Phase 3: Antemortem Information Retrieval
• Police gather information about possible victims, such as
• descriptions of appearance, clothing, jewelry, photos
• medical and dental records, x-rays
• fingerprints, from objects or official records (commonly collected by some overseas agencies)
• DNA samples, such as from a hairbrush, toothbrush or blood sample.
Phase 4: Reconcilliation
• Information from postmortem and antemortem phases are brought together to find a match
• Easiest identifications are done first to reduce the possible number of matches
• Identification Board (chaired by the Coroner) is presented evidence of the match by fingerprint, dentistry, DNA and Police DVI experts and decides if identification has been established
• Family and/or Foreign Mission is advised, then media.
Phase 5: Debrief
• People involved in the DVI process keep each other updated throughout all stages
• Support and welfare is made available to staff including stress and grief counsellors, chaplains, Victim Support and police welfare officers.
When can a body be identified relatively quickly?
• The death was witnessed by someone who knew the victim
• The victim lived locally so samples and records can be easily accessed.
When does it take a relatively long time to identify a body?
• Descriptions have changed, such as the victim changed clothing
• The victim was seriously injured
• Results from samples and/or records have to be arranged from overseas.
Why isn't it enough for a friend or relative to identify a body?
• International experience shows visual identification is not conclusive. Those trying to make an identification are highly stressed and mistakes occur.
• Severe injuries can make visual identification difficult.
How long does the DVI process take?
• It depends on factors including number of people available to work on it. DNA samples usually take several days to process.
• Police are retrieving information (Phase 3) from people reported missing while searches continue.
How are families kept informed?
• A Police family liaison officer is assigned to families of people reported missing. They provide a consistent point of contact, inform families about the process and update them with progress.