Digging up the past

A “meticulous, light touch” is required when human remains are discovered.

If people rush, they make mistakes and risk missing vital clues.

So says former detective Gerry Kealy, who was known as “The Bone Man” in the force, where he worked for 34 years.

The part-time Sligo IT lecturer is one of the country’s foremost experts of scenes of crime analysis and forensic science investigations.

As searches continue at Killakee in the Dublin mountains, where human remains, confirmed yesterday as missing woman Elaine O’Hara, were found last Friday, Mr Kealy said a “vast picture” can be built up from bones and the site.

“If remains are discovered, you don’t want to do further damage to the scene until people who know what they are doing get there,” he said.

He said he wrote a “step-by-step” procedure for scenes of crime investigations for the gardaí: “It’s the type of investigation that can’t be rushed. You can’t make a mistake. If you rush, you will miss vital clues. A light touch approach is needed.”

Preserving the scene is one thing, but determining how far to preserve is another, said Mr Kealy.

“Scavenging is an issue. You can end up with partial skeletal remains. Animals and birds will drag them away, bury them. So you need to look for fox holes, badger holes, they can pull things in. Also, birds can pick things up, can use hair for nests — even bits of skulls, so you need to look up as well as down.”

He said the first thing investigators do to identify a person is to try and determine sex, age, and race. They will also check any pockets in case they hold identification or dated receipts. He said the shops in question can then be checked to see if security footage captured them at the time of the purchase.

Barring that, pathologists and forensic anthropologists will conduct further examinations.

“The jaw bone tells you the sex. They will also look at the pelvic bones or the skull. Women’s bones tend to be lighter.”

He said leg bones such as the tibia or fibula can help show the age of the person, as will any presence of arthritis. He said the long bones (fibula and tibia) can also give approximate assessments of height and stature.

In Ms O’Hara’s case, experts found a tibia, fibula, a jaw bone, and part of a pelvic bone, so they have a lot to go on, said Mr Geary.

He said the general conditions of the bones, including their weight and colour, provide clues, including how long they have been buried.

“If the bones are there 20 years they will be very light, very weathered, coloured. Fresh bones tend to be heavier, waxy, have moisture content.”

In the Killakee case, gardaí were able at an early stage to say the body had been there a maximum of two years, and that it was a woman aged between 25 and 40 and of heavy build. This and other information from the scene “narrowed the range” to nine missing women, before being confirmed yesterday as Ms O’Hara.

Mr Geary said bones can also show if a person had surgery and had previous injuries, which all might go to identifying him or her. He said teeth were the “best source” of DNA samples, as the enamel protects the pulp in teeth. He said long bones could also give DNA samples.

Examinations will show if the person had suffered violence, such as beatings or fractures, and whether they had been stabbed or shot. He said if the hyoid bone in the neck is broken at the time of death it could indicate the person was manually strangled.

Mr Geary said a meticulous search of both the site where the remains were found and the general area was crucial. He said personal items could be recovered, such as jewellery, clothes, footwear and glasses.

He said it might also throw up clues as the killer: “Burying is something done on your own, in the dark and in seclusion. Sometimes clues can be left, something can be dropped unknowingly.

“It’s so important to do a finger-tip search, to sift through the soil, for clues. You are trying to gather as much as evidence as you can from the scene to determine what exactly took place, how they got to the scene and how they left. It’s a meticulous, step-by-step approach.”