Dawson’s colleague at the Macaulay, Professor David Miller, is a specialist in landscape reconstruction. He coordinates a 40-strong international research team – Geoforensics and Information Management for crime Investigation (GIMI) – that is developing non-invasive ways of recognising the graves of murder victims or buried artefacts. The team is focusing particularly on geophysical techniques such as magnetometry and resistivity – the measurement of the variation in the Earth’s magnetic and electrical fields caused by buried objects. Such techniques will be familiar to viewers of the Channel 4 television programme Time Team, but they have rarely been applied to crime scenes.

 

Conventional remote-sensing technologies such as aerial and satellite photography are also useful in forensic investigation, especially when particular parts of the spectrum can be highlighted or eliminated. For example, infrared light is useful for detecting the heat given off by buried bodies as they decompose.

 

“Even the most careful murderer would be hard pushed to restore all of the layers of soil after burying his victim,” says geophysicist Alastair Ruffell of Queens University, Belfast, a specialist in remote-sensing technology and a collaborative member of the GIMI network. “We can use multi-spectral imaging to highlight areas of soil disturbance where the underlying geology has been brought to the surface.”

 

Another geophysical technique being applied is radar interferometry, an extremely sensitive form of aerial radar that can detect differences of only a centimetre in ground height – enough to reveal sinkage caused by an earlier burial.