Following advance for use at 2 p-m, E-S-T (Washington-AP) -- Questions are being raised today about a scientific method the F-B-I uses to match bullets from some crime scenes.
The National Research Council says a relatively infrequent technique known as "chaining" can result in a high rate of false positives.
"Chaining" is used when there's too little of a bullet fragment to do other tests. Scientists then try to match the chemical composition of the fragment to that of other bullets found in a suspect's possession.
But researchers say bullets sold together in one package are not all necessarily from the same batch of melted lead.
F-B-I Lab Director Dwight Adams says chaining has only been used in 25-hundred cases since 1980. He says the report doesn't say the F-B-I should stop using the technique -- but instead says the method should be enhanced.
The head of the research panel says the top recommendation is that F-B-I experts tell juries the limitations of the test.
The National Association of Criminal Defense Lawyers says the report could affect cases now on appeal, adding that the "chaining" method gets much more credibility than it deserves.
Suspicious, probably. Conclusive? Nah.
