THE FBI has suspended use of a controversial technique for matching bullets from crime scenes to unused ammunition in a suspect’s possession, it emerged last week.
The technique in question relies on variations in the levels of trace elements in refined lead to identify the batch to which a bullet belongs. But as New Scientist revealed three years ago (20 April 2002, p 4) there are serious doubts about the technique’s validity. The ratios may not be unique, and the batches of lead are so large that it may be impossible to distinguish bullets made months apart.
“The number of bullets from a single batch…
