KEY POINTS:
Poor old Sir Arthur Conan Doyle's super sleuth has done his chips. These days, advances in forensic science have thrust aside Sherlock Holmes in favour of white-coated (generally attractive size-eight female) scientists as the stars of the pop crime genre.
With a galaxy of extraneous DNA clinging to his tweed jacket - to say nothing of the the ash raining from his pipe - Holmes would have been deemed a contamination risk and kept well away from their crime scenes.
Brilliant deductions are all very jolly, but these days, what is elementary is invisible evidence. People with post-graduate qualifications in fields of science most of us can't pronounce scan crime scenes in the real world clad in anti-contamination suits and bonnets to protect the clues we cannot see or readily comprehend.
No longer is the crime show a battle of wits between detective and criminal, where Peter Falk's rain-coated detective Columbo pauses while leaving to deliver the question that exposes the culprit.
The new detectives have names such as Dr Temperance Brennan and Dr Kay Scarpetta. They are scientists, like crimewriter Kathy Reichs, a forensic anthropologist, who created Dr Brennan.
Scarpetta's creator, Patricia Cornwell worked for six years in the Office of the Chief Medical Examiner of Virginia as a technical writer and computer analyst.
The British television series Silent Witness, now showing on TV One, is in its eleventh series and the American CSI is up to its eighth season.
Pollen traces on a sleeve, the chemical structure of a rope used to bind a victim, a blood splatter pattern, what maggots tell about the time of death, fibre analysis; such is the stock in trade of the new detectives.
And such is the subject of the latest book by Otago author and former policeman Bill O'Brien.
O'Brien, 61, became a fulltime writer when he handed in his blue uniform after 35 years.
Invisible Evidence is the latest of more than 20 books the Mosgiel writer has churned out since 1991.
His first chronicled a tragic and heroic piece of Otago history, but is known best as the basis of a film.
Aramoana: 22 Hours of Terror was published in 1991. Many years later, Stephen O'Meagher picked the book up in a Ponsonby secondhand book store. He recognised the scope and import of the story but, more importantly, realised that it could be translated to film.
Last year, Out of The Blue premiered in Dunedin.
"I thought it had to be recorded for history and done properly," says O'Brien. He was well placed to do it.
He'd just sunk into his armchair at home on November 13, 1990 when the phone call came asking him to return to work.
Deranged loner David Gray was on the armed rampage during which he killed 12 people in the seaside settlement of Aramoana.
O'Brien handled media calls from around the world, and was in radio contact with the members of the armed offenders and anti-terrorist squads as events unfolded.
It was a dark chapter, but one with many acts of bravery. Everyone he approached for his book agreed to be interviewed, and many have become friends. He recorded it as it happened - the shock, the dumb luck, the grief and the quiet heroism.
The first publisher turned the book down, thinking it would be written in policespeak, says O'Brien.
"I think I've proved them wrong, especially with the film being made because the producer read the book and thought it was a hell of a story."
Crime is again the backdrop of book number twenty-something.
Invisible Evidence tells the story of the development of forensics, focusing on work being done in New Zealand.
O'Brien aimed to explain complicated science to secondary school students, and while his book aims to inform rather than thrill, he provides many examples of how the techniques have been applied in investigations.
For instance, how analysis of isotopes enabled the origin of a boy's torso found in the Thames in London to be traced to a town in Nigeria.
Applying the same science in New Zealand, scientists can tell by isotopic analysis of its cells whether a fish was caught on the east or west coast.
For an old cop, it's a new world. And it's not restricted to DNA advances such as low copy DNA whereby a genetic profile can be lifted from a couple of cells left, for example, on a pen.
"There's palynology, the arrangement of pollen you might get on the victim and the suspect. If they match, you know they came from the same environment."
O'Brien cites a sex case in which the victim claimed she was dragged behind bushes, while the accused man claimed the encounter occurred some distance away in the open and was consensual.
The same concentrations and combinations of pollen were found on the clothing of both, and they matched the environment described by the woman.
Pollen provided a lead in the unsolved murder of Kirsa Jensen. Her horse was found tethered to a gun emplacement on the Awatoto seafront near Napier but she has never been found. The rope used to tie the horse did not belong to her or those who found the horse and was therefore thought to have belonged to her killer.
A palynologist's examination of the rope found pollen with concentrations of pumpkin, beetroot and broad beans, indicating the rope came from a market garden or a large private garden.
The main suspect worked in an orchard where police found pumpkin, beetroot and broadbeans in flower.
Another forensic field is the use of computer models to analyse blood spatter.
Says O'Brien: "By examining the width of a blood spot, it's possible to gauge the angle it came from and from there work out whether someone was standing or lying ... and then negate or corroborate the defence of an accused who says it was a fair fight.
"Well, it wasn't a fair fight if all the injuries came when the person was on the ground.
The book taps in to the current fascination for forensics. During his research for the book, O'Brien found that on a particular Thursday night in the United States, 27 per cent of viewers were tuned to this type of programme. Eight were among the top 20 shows.
A look at New Zealand television listings suggests the field is of no less interest here.
Not that such programmes are always realistic. They tend to show data being fed into a computer that immediately spits out a result.
"What I've tried to do," says O'Brien, "is show how it's done in the real world. Nothing substitutes for real hard work."
That applies to O'Brien too. He's a painstaking researcher who toured New Zealand interviewing scientists for Invisible Evidence. He writes his first and second drafts in longhand, then does a typed draft which receives several edits.
Though he describes his writing as a hobby, it occupies him for at least as many hours a day as he worked as a policeman.
He writes fiction and non-fiction, short stories for educational publications and novels, and says it's serving its purpose of keeping him going.
"I went to a retirement function for a colleague and I said to him, 'what are you going to do on Monday'. He said, 'I don't know'. I didn't ever want to be in the situation where you don't know what you are going to do next."
He's most proud of a Castaway, a historical novel for children about a shipwreck on Disappointment Island, in the Auckland Islands, in 1907 and the eventual rescue of 14 survivors.
It was a finalist in its category in the New Zealand Book Awards. "To be in the top five in the country, that's not too bad for an old cop."
O'Brien gets a kick out of having been able to make a living as a writer despite the doubts of the publisher who turned down Aramoana, and a reviewer who liked the book but was unflattering about O'Brien's writing.
That was 16 years ago and it still motivates him.
"I thought, right, when I get to my 100th publication it would be fair enough for me to remind him and say 'not bad for someone who can't write'."
Invisible Evidence: Forensics in New Zealand is in book stores now.
