Top forensic pathologist Simon Stables identified bodies after the Thailand tsunami and the Christchurch earthquake. He appears in the new season of Forensics NZ on Prime.
1 What does a forensic pathologist do?
Sudden and unexpected deaths are referred to the coroner, a lawyer who decides whether an autopsy is needed. Pathologists - specialists doctors - perform the autopsy and give an opinion on the cause of death.
We perform about 250 autopsies a year each. Only about 10 per cent would be suspicious; once you've ruled out other explanations like accident or natural death only about five per cent end up being homicides. Suicides make up a significant proportion of our work. Motor vehicle accidents and cot deaths have decreased.
2 Do you perform autopsies in the middle of the night?
When I started 22 years ago we did. Biological evidence deteriorates over time so the sooner you do an autopsy the better but you have to balance that with the need for quality evidence. People who are tired don't function as well.
You can't afford to miss or misinterpret evidence so if police have been up all night investigating we find it's better to wait until everyone's refreshed. You only get one shot at a post mortem.
3 What are the most common misconceptions about forensics to come from TV dramas?
It is impossible to give a precise time of death. There are just too many variables. Also we can't confirm the cause of death in about five per cent of cases.
4 How do you think of your relationship to the deceased?
I think of myself as their last doctor. It's my job to tell what's happened to them on their behalf. Sometime family members want to know, 'Is there anything I could have done to prevent it?'
Being able to provide families with answers can provide a little bit of comfort. Sometimes information can save lives, for example genetic conditions that may run in a family.
5 What has been the biggest technological advance in your field in recent times?
CT scanning has become a bit part of the job in the last 10 years in response to growing public opposition to post mortems, especially from the Jewish community. CT scans allow us to get a large amount of information without doing an internal examination.
You can see if there's a bullet, a bone fracture, or an infectious disease like TB. However a CT scan can't tell you everything, so it's not a replacement for post mortems but it is a very useful screening tool.
6 Have you ever had to do a post mortem against the wishes of the family and has that been a difficult?
The decision on whether to proceed with the post mortem is the coroner's. In the cases of homicides and suspicious deaths, the family don't have the right to object. If the coroner wants a full post mortem done, I'll do it.
7 Have there been cultural advances made in the field of forensic pathology?
I think there's greater understanding now. We're very much aware of Maori cultural requirements. For example, they consider the head to be sacred so we will avoid opening it if we can.
If there's an objection, we'll discuss with the coroner whether a full post mortem is needed. The other major concern is returning all the body tissues and fluids. If we have to send a sample to toxicology, we take tiny amount - no bigger than a thumbnail and when we've finished our work, sometimes months later, families are entitled to have those specimans returned.
8 You were awarded an MNZM for your services to disaster victim identification (DVI). Which was the hardest disaster zone you worked in?
The tsunami in Thailand was the first real big one and that was eye opening in terms of the sheer scale. There were 5,000 deaths in the Phuket area. You'd clear one area of bodies and then a truck would arrive with hundreds more.
A lot of the skills our team of New Zealand police and DVI specialists learned in Thailand we used in Christchurch after the quake. We had to set up a temporary mortuary so it was; 'Right, we need a shed, we need trolleys, we need to get power and water in there, what are we going to do with the dirty water?' It took us two and a half days to have it up and running.
9 How did your work help?
The first task is identification. You don't want to send home the wrong person, as happened recently in a high school bus crash in Canada where one family was told their son was in a hospital bed when he'd actually died.
In Christchurch we were also able to document injuries and give an opinion as to the cause of death which turned out to be very important later at the inquests.
10 You've given evidence in court on some of New Zealand's most high profile murder cases. What was the most interesting?
The Stanlake case, which is in the Forensics television show; a handless body was found on a Wellington beach. I jumped on a plane and performed the post mortem that afternoon. Even though his hands had been removed, there was a tiny piece of palm left - just enough to match to prints on police records. Knowing who it was made the investigation much easier.
11 Internationally there is a shortage of forensic pathologists. Do you think people are put off because it's perceived as too gross?
The morbidity is a factor. I know people who have dropped out because they got sick of dealing with death every day. Also, it's not well publicised among med students as a career option.
I enjoy the mystery of it. You've been given the circumstances and you've got to work out if they're consistent with what you're finding. Somewhere in the body is the answer. It's especially satisfying if you can prevent further deaths.
12 What's the hardest part of the job?
Balancing the workload. It's completely unpredictable. If you're on call you've just got to go. For stress relief, scuba diving is my passion. I'm not a hunter gatherer, I'm quite happy just to sit down there and float, knowing that no one can get hold of me.
• Forensics NZ airs on Prime, Sunday nights at 8:30pm