The science of searching

Advanced techniques could be key in search for Suzy Lamplugh

How do you search for a needle in a haystack? This week police are searching fields and ponds in Worcestershire in an attempt to find the body of Suzy Lamplugh, the estate agent who went missing in 1986. BBC News Online's Finlo Rohrer finds out how technology can help.

The art of applying forensic techniques to locating bodies hidden for months or years has advanced rapidly since police searched for victims of Moors murderers Myra Hindley and Ian Brady in the 1960s.

In the 1980s police returned to the Moors with Brady to search for more of his victims.

Key techniques

Magnetometry - Dectecting anomalies in the grounds magnetic field caused by shifted earth

Resistivity - Areas of especially low or high resistance to electric current may indicate a body is present

Ground penetrating radar - Especially effective at detecting bodies buried in concrete

Then in 1994 Gloucestershire police spent months searching for the buried victims of Fred and Rose West.

Throughout these inquiries, and others, police have often required the services of experts steeped in forensic techniques.

Police searching for the body of estate agent Suzy Lamplugh, missing for 14 years, have already called on the services of the Bradford-based Forensic Search Advisory Group.

Experts from the group have been involved in dozens of cases in the 1990s with one search taking Detective Sergeant Mick Swindells and Professor John Hunter to the Falklands to search for the body of young Royal Marine Alan Addis, missing since 1980.

'Cadaver dogs'

Prof Hunter, a forensic archaeologist, has already visited the site of the current search for Suzy Lamplugh at Norton Barracks, Worcestershire.

Det Sgt Swindells, who specialises in training the "cadaver dogs" that search for hidden corpses, is one of only two police officers in the FSAG, which is dominated by academics.

Speaking to BBC News Online, he explained how experts search for a buried body in an open location such as a field.

Search experts first talk to investigating officers, getting a feel for how strong particular leads are and rating possible search locations.

Once a search area has been identified, experts examine aerial photographs of the site as it is now and compare it with pictures of the same site taken by Ordnance Survey or other sources prior to the suspected crime.

Fred West: Hunt for bodies led to advances in some search techniques

The next step is for investigators to visit the actual site where the body is thought to be buried.

Det Sgt Swindells said: "We are looking at changes in vegetation, depressions, excess soil. Soil starts to compress, you end up with a depression and after the body has collapsed you end with a secondary...another little depression in the middle."

"Probe holes" are dug in likely sites, allowing cadaver dogs to sniff for remains.

Police are able to use a database containing statistical analysis of how murder victims were buried when identifying possible sites, but Det Sgt Swindells emphasised the importance of common sense.

He said: "There is no way that anybody is going to bury anybody on a motorway roundabout - it is too open."

Search for those murdered by Fred West brought use of radar to public attention

Det Sgt Swindells was able to use his knowledge to find the body of murdered five-year-old Rosie McCann, after police in Oldham, Greater Manchester had drawn a blank in the seven weeks after her disappearance.

The girl had vanished from her home in January 1996 and pub DJ Andrew Pountley, an ex-lover of her mother, was later jailed for life for her rape and murder.

A search of the area around a disused railway line near Pountley's home led Swindells to discover the child's body in a sports bag in an alleyway.

If they have a general area for looking for Suzy Lamplugh, that is just the start

Prof John Hunter

Prof Hunter said tests involving radar, magnetic polarity and resistance to current also had to be augmented by common sense.

"Various tests have been developed over the last 10 years, mostly involving geophysical methods, magnetic change, resistance but there are limitations and you normally take a whole battery of techniques."

He said ground penetrating radar, used during the Fred West investigation, could not be used everywhere.

"The system looks for changes in density of materials - when you have got decomposing remains or skeletal remains it is not easy."

Techniques have advanced since 1960s Moors search

The radar, although particularly useful for bodies buried in concrete, also does not work in clay.

Prof Hunter admitted, as in the search for IRA victims in Northern Ireland, it was often difficult for witnesses or killers to remember exactly where bodies were buried years after the event.

He added: "It is very difficult to pinpoint years later - even if they have a general area for looking for Suzy Lamplugh, that is just the start. They have to use every trick in the book."