Oswald Tested Positive

The FBI failed to determine whether accident or intent contaminated evidence against Oswald.

The Oak Ridge National Laboratory found barium and antimony on both surfaces of paraffin casts made from Oswald's right cheek. They correctly concluded that the barium and antimony found on the outer surface of the cheek cast that was not in contact with Oswald's skin came from an external source.

Their finding of a greater amount of barium on the outer surface than the inner and nearly equal amounts of antimony on both sides were evidence that the barium and antimony on both sides of the cheek cast came from a common source of contamination.

Furthermore the amounts of barium and antimony were consistent with firing a weapon and greater than expected by accidental contamination. These findings of incriminating evidence in the wrong places should have prompted a thorough and scientific investigation.

Although common items contain barium and antimony compounds, these chemicals belong to unique mixtures that distinguish one contaminant from another. By identifying all the contaminants, the W.C. could have shown feasibility of contamination by accident.

On the other hand, analysis of the contaminants had risks. For example finding reagent-grade barium and antimony would have proved Oswald tested positive for planted evidence.