This personal attack on the forensic scientist is unusual because there was the opportunity to kill him. This was also a personal attack as opposed to the other bombs placed that put evidence from crimes under investigation at risk.
Then there was the scientist who "fell"-"jumped"-"was tossed" off the bridge. he was nosey too but it's unlikely that the mob would be too nervous about his research.
The mob [*outfit* in the environs where I worked in the newspaper racket] is not at all so generally disposed, but has cooperated in the past with US Government intelligence agencies requiring either local talent or no direct links to a death that may be required, as with that of Fidel Castro at the hands of former Havana casino operators, or of Martin Luther King by crooked cops on the payroll of the Carlos Marcello family of New Orleans...which took place in Memphis. Just a coincidence, I'm sure....
I could also well imagine that the mob, which has long held interests in certain legitimate businesses such as hotels, waste removal and the liquor distribution business might easily diversify into pharmaceuticals, and at least one way of preventing a breakthrough advantage by a competitor might be to remove the individual responsible for that advance, if he could not be bought off. Do you reckon that Dr. Wiley was the sort of fella who could have been bought off easily? If not, a local cop on the outfit's payroll could have handled the job neatly, and that might easily explain the Memphis PD determination to write off the physician's disappearance as a suicide or accident.
Such a drastic step would of course not be likely if but a few thousand dollars were involved, though certainly men have been murdered for less, but if a multimillion-dollar breakthrough drug or treatment were involved, I might be wary about selling life insurance to those involved.
-archy-/-