Researching skeletal remains in DI Andy Horton mystery THE RAT ISLAND MURDERS

In THE RAT ISLAND MURDERS ( DI Andy Horton Solent Murder Mystery 14) five skeletons are discovered on a small uninhabited island, owned by the Ministry of Defence, in Portsmouth Harbour between the town of Gosport and the city of Portsmouth.  Rat Island was used as a burial ground for French prisoners from the prison hulk, HMS York, between 1819 and 1854. 

The onsite  forensic archaeologist, Dr Lauder, had deemed them all to be from the nineteenth century but after further analysis in the lab, he discovers that one of the skeletons is much more recent, and clearly she'd been murdered. It's DI Andy Horton's task, along with the Major Crime Team, to find out who she was and who killed her.

Here are some interesting facts I unearthed during my research.

Having ascertained the remains are human, the next question is to find out if they are contemporary, i.e. did this  person die within the last fifty years? If so then they would be the focus of a criminal  investigation.

A more recent death can show up in the  colour of the bones which hasn’t absorbed as much of the surrounding soil as the other bones. The bone quality is far more superior in a more recent skeleton. High levels of carbon-14 in the tissue can indicate that the remains date within the last  sixty years.  This is due to the fact that the United States, and several other countries, tested nuclear weapons above ground during the fifties and sixties. The Nuclear Test Ban Treaty of 1963 effectively ended this. Since then atmospheric carbon-14 levels have been declining as the radio carbon is soaked  up by the oceans and the biosphere. So, the longer someone was born after 1963, the less artificially high levels of carbon-14 there are.

• Tooth enamel,  tooth collagen and bone collagen can help determine year of birth.

• Gender can be determined by the pelvis. The female pelvis is smoother, lighter and more spacious than the male pelvis and the body of the pubis is quadrangular rather than triangular in shape. The sacroiliac joint is  small.The skull is the only reliable bone in determining  race.

• Stature can be determined from the femur, tibia  and humerus. Age by examining the fusion of bone ends to bone  shaft.

• A skull can be scanned into a computer programme and the face can be fleshed out to give an idea of facial appearance in  life, but it can’t determine the colour of the eyes, hair or the shape of lips.

• Different geographical locations are known to have  different, often distinct, isotope ratios.  There are four stable isotopes, and  because their ratios vary between different geographical locations, people and animals will ingest food and water from those locations. Therefore, the  analysis of the ratio of isotopes found in the bones can indicate where the person  lived.

• Bone contains very little nuclear DNA but it does contain mitochondrial DNA  inherited from the maternal bloodline, which lasts longer than nuclear DNA.

So there you have it.  Dr Lauder can advise Horton but it's down to Andy to find the killer of the fifth skeleton.

This was originally published as Dead Passage.

Available on Kindle, Kindle Unlimited and in paperback. Published by Joffe Books.