Three men were tested for gunshot residue after a fatal shooting.
All three tests were negative.
But prosecutors still told the jury that one particle on the defendant’s hand and another on his shirt helped show he was the shooter.
There was a problem: the state’s own expert said a positive test required at least three particles, and that nothing could be drawn from a negative result.
The Massachusetts Supreme Judicial Court found the evidence unreliable and prejudicial enough to warrant a new trial.
It’s a useful example of how forensic evidence can sound far stronger to a jury than the science actually supports.
-The Criminal Defense Brief