The Law: Who Confessed?

On Oct. 22, 1972, two boys trudging through a remote cemetery near Scranton, Pa., found the body of a woman who had been stabbed to death. Later that day, a man who identified himself as Roger Ferretti telephoned Scranton police to report that he had just killed a woman—and the call was routinely recorded. The cops located Ferretti, who denied killing the woman or making the call. Two days later police arrested Adam Topa, now 56, a factory worker who knew Ferretti and had been out drinking with the victim the night of the murder. The evidence against Topa was strong but largely circumstantial: bits of wool found on his bloodstained jacket matched the woman’s coat. The most striking evidence came from a sound spectrograph, a machine that reduces speech to electronic “pictures” called spectrograms or voiceprints. Lieut. Ernest Nash, Michigan State Police expert, testified at Topa’s trial in 1973 that the voiceprint of the telephone confession matched Topa’s, not Ferretti’s; he also argued that voiceprints were as accurate as fingerprints.

Topa was convicted and sentenced to life imprisonment. Last week the Pennsylvania Supreme Court disagreed with Nash, arguing that “his certainty is not shared by all commentators and scientists in the field.” Unlike fingerprints, the court noted, spectrograms may vary according to such things as the speaker’s health or age. And like a lie detector test there is a risk that the jury will give too much weight to such testimony. Though top courts in two states admit voiceprints as evidence, the court decided that Pennsylvania would not join them until there was “general acceptance” of the precision of voiceprints among experts. The court then ordered a new trial for Topa.