Stotts v Heckler & Koch

299 F. Supp. 2d. 814 (WD Tenn. 2004)

Unsupported statements of opinion by experts are simply not good enough


This was a claim against the defendant gun manufacturers following an accident involving the plaintiff, a police officer in Tennessee, in which a gun made by the defendants discharged whilst being cleaned by the plaintiff. The bullet went through his right eye and brain.

The defendant filed motions to exclude expert testimony by Dr Peretti, a forensic pathologist, and by Dr Block, a metallurgic engineering expert. The plaintiffs filed a motion to exclude the testimony of Mr Shain, the defendant’s firearms safety and function expert.


It was contended by the defendant that Dr Peretti’s testimony, which was to the effect that the injuries had not been the result of a suicide attempt, and that the gun more probably discharged when dropped, was not admissible insofar as it is unreliable and based on speculation.

It was contended that Dr Block’s testimony, that the gun was capable of malfunctioning if the hammer was manually lowered, and that there was insufficient warning of this accompanying the gun, was inadmissible insofar as it was speculative and contained matters that were apparently contradictory.

The plaintiffs, in turn, contended that Mr Shain’s evidence, that the injuries were not the result of a ‘drop fire’ incident, was inadmissible because his experiments were inadequately documented (for example, as to height from which gun was dropped).


In respect of Dr Peretti, his testimony was excluded in part. The court rejected his opinion about where the gunshot occurred, about whether the gun was in ‘double action mode’, and about whether the gun discharged when dropped, based “primarily on the unsupported assumptions, lack of evidence and lack of scientific reasoning supporting the methodology by which Dr Peretti founded his opinions on those matters.” His testimony on whether the injuries were the result of a suicide attempt, or the work of another person, was admitted as being within his competence.

In respect of Dr Block, his testimony was admitted in full. His professional expertise and methodology satisfied the Daubert test. The fact that certain matters appeared, in the defendant’s case, to be contradictory, was a matter for weight not admissibility. The Federal Rules of Evidence did not require independent testing, and so the fact that Dr Block had written his reports prior to carrying out the drop tests did not make the testimony inadmissible.

In respect of Mr Shain, the court admitted his testimony. Although it noted that there was an absence of some documentation of the testing he had carried out, those tests had been video recorded, which provided sufficient documentation as to make them reliable.


Expert evidence must be produced in an objective manner and the underlying views or opinions expressed by the expert must be demonstrated in the body of the report by logical and objective reasoning and, generally, be supported by reference to documentation. 

In both the USA and in England and Wales, bald unsupported statements of opinion by experts are simply not good enough – they will either be excluded or accorded little (if any) weight.