Forensics: What Bugs, Burns, Prints, DNA and More Tell Us About Crime

by Val McDermid

Together they decided that for his dissertation he would look into the ability of smoke alarms to wake children. They asked the parents of thirty children to set off the smoke alarms in their properties at random hours of the night. ‘Eighty per cent of these children did not wake up, even though some of them had the alarm in their bedroom.’

At first a body relaxes completely, then after three or four hours the small muscles of the eyelids, face and neck begin to stiffen. Rigor progresses downwards, from head to toe towards the larger muscles. After twelve hours the body is completely rigid and will stay fixed in the position of death for around twenty-four hours. Then the muscles gradually relax and stiffness goes away in the order in which it appeared, starting with the smaller muscles and progressing to the larger ones. After a further twelve hours or so all the muscles reach a state of complete relaxation.

In Stafford-Smith’s words, ‘Capital punishment means those without the capital get the punishment.’

But, however personally stressful a forensic scientist may find giving testimony, the courtroom is the anvil on which scientific evidence is struck. With a well-prepared lawyer playing the part of the hammer, forensic techniques are either strengthened or broken, according to their merit.