But CNN has learned that the inmate has failed a number of liedetectortests regarding the details -- described by some sources close to the investigation as vague -- of the plot.
This remains only a suspicion, however, because the results of these lie-detector tests (administered under circumstances unclear to Sutton Associates) cannot entirely be trusted.
The company took a hit in 1988 when lie-detector tests were made illegal for employment purposes, so Argenbright, who says it made him "focus like a blowtorch, " threw himself into building the aviation services and security business.