The first bodies began arriving at Colombo's main mortuary half an hour after suicide bombers attacked a series of churches and luxury hotels in Sri Lanka on the morning of Easter Sunday.
Many of them were badly damaged and peppered with shrapnel wounds, Chief Consultant Judicial Medical Officer Dr. Ajith Tennakoon told Al Jazeera, pulling open a drawer in his desk to take out a plastic evidence bag containing a silver ball-bearing measuring only a few millimetres across.
"This is something that we never expected," Dr. Tennakoon said of the attacks, which the government blames on a local Muslim group National Thowheed Jama'ath (NTJ).
"People were shocked. Really shocked. Even us looking at dead people, hearing those many, many sad stories."
The scale of the disaster - the biggest attack in the country since the long-running conflict with the separatist Liberation Tigers of Tamil Eelam (LTTE) ended a decade ago - added to the pressure on the authorities to help families find and identify their loved ones in a timely manner.
By Wednesday, the death toll from the attacks, which also targeted two churches outside Colombo, had risen to 359.
But late on Thursday the Ministry of Health abruptly revised the figure down to 253, blaming the difficulty in identifying the bodies. The ministry's Director General did not return Al Jazeera's calls for comment.
The sharp drop in the death toll followed earlier revelations that the government had failed to act on warnings from international intelligence agencies that attacks were imminent, adding to questions about the government's handling of the crisis.
Richard Bassed, a Disaster Victim Identification (DVI) expert with the Victorian Institute of Forensic Medicine in Australia who worked to identify the dead in the 2002 Bali bombings and the 2004 tsunami in Thailand, says double-counting is common in any large-scale disaster such as a bombing.
Multiple relatives may report a person missing, or a family member may turn up alive in hospital because they had simply not been in a condition to communicate their name at the time they were admitted.
And when bombs blow bodies to pieces, parts of different people may end up together in a body bag, making it difficult to separate one person from another.
Nevertheless, while forensic scientists need time to establish a victim's identity conclusively, for governments time is of the essence.
"For about 300 people, it should take five to six months to identify them all properly to Interpol standards including DNA, finger-printing, dental records, all those sorts of things," Bassed said.
"But the government will be saying it's got to be done in a week. They will just want to get it over with."
The mortuary tagged each bag as it came in - whether it contained a single body or parts - and began the process of visual identification - displaying the photos of the deceased to waiting families - to help people find their loved ones. Counsellors were on hand to provide support to the bereaved.
On Monday, a family group was waiting outside the mortuary gate to take home the bodies of their grandmother, Poorna Mary, aged 60, and her grandson, Moses Prashant, 15, who had been eating breakfast at Colombo's Cinnamon Grand hotel when the bomber detonated the explosives in his backpack.
"There are a lot of body parts," said one of the young women who had worked on the identification.
"It was very difficult. For the grandmother, we had to identify her by her teeth."
Interpol recommends a four-step procedure to identify the dead following a disaster covering: the scene of the crime, the type of evidence that can be used to establish a person's identity, the best way to discuss the issue with family members and the final measures needed before the body can be released to relatives for the funeral.
The guidelines acknowledge that the process can be "often very challenging", especially when there are mass fatalities.
"It's traumatic and challenging, but when it's done properly is enormously rewarding," Bassed said of the job.
"And when the families get their remains back they will know for sure that it's their loved one."
The mortuary in Colombo, tucked away in a crumbling colonial building on a narrow lane near the National Hospital, accepted victims from the three hotels - Shangri La, Cinnamon Grand and The Kingsbury - that the bombers targeted, as well as St Anthony's Church.
The victims the hospital was unable to save were also transferred to the morgue.
Dr. Tennakoon said Sri Lanka developed its guidelines on disaster victim identification from both Interpol and the International Committee of the Red Cross and had refined them in light of its experiences responding to atrocities during the civil war.
By Sunday afternoon, staff washed blood from faces - assuming the victim had not been completely disfigured - and cleaned up battered bodies to try and reduce the trauma of having to identify a loved one who has died. By Monday, bodies were leaving the morgue and being prepared for burial.
As of Friday, 96 complete bodies - 24 of them foreigners - had been identified and released to their families, Dr. Tennakoon said.
Three Danish victims were identified through DNA, some of the British victims from dental records and the four Chinese victims from their fingerprints.
Some 18 complete bodies are still to be identified - 17 of them foreigners - and the forensic team expects to start tackling the 49 bags of body parts soon, the doctor said.
Those bags may contain the parts of more than one person, or the parts of a person who has already been identified, suggesting the toll could still be revised.
The mortuary has been notified of at least seven missing people, but the records will need to be cross-checked in order for the victims to be positively identified.
It is likely that some of the bodies may never be identified at all, Bassed said, noting that the identities of some 400 victims of the tsunami that devastated the Thai coast around Phuket in 2004 remain a mystery.
Dr. Tennakoon has been a pathologist for 30 years and worked three days straight as the tragedy unfolded. He says his Buddhist beliefs help him cope with the demands of his work.
"My job is to give my service in a proper, dignified and respectful way to the dead and the people who are grieving."