Hired Guns : Establishing the Scope of the Proper Cross-Examination and Argument Relating to Expert Witness\u27 Compensation in Criminal Trials

Abstract

The outcomes of criminal cases can turn on the credibility of the parties’ expert witnesses. The compensation such experts receive in exchange for their work on cases can undermine their credibility, as it provides the experts with a financial incentive that might bias them in favor of the parties who retain them. While concerns with such bias have existed for decades, courts have been inconsistent in the defining the permissible scope of cross-examination and argument on the issue. Some courts have unduly curtailed such cross-examination and argument. Courts have also been inconsistent in their views of whether calling such expert witnesses “hired guns” is proper argument. The present article begins with an overview of the issue, providing examples of the types of cases in which the issue may arise. The article then explores the general standards of conduct that govern the conduct of both prosecutors and defense counsel. Next, the article proposes standards defining the scope of proper cross-examination and argument on the issue. Finally, it proposes standard jury instructions that can be used to undermine the effect of improper argument on the issue