concurring:
While I concur generally with the majority, I add a cautionary note. May, who testified against Bernard and Comstock, was an accomplice to their activities, a paid informant for the government, and a drug addict. Part II of the majority opinion suggests that it would have been “better” for the district judge to give a jury instruction mentioning all of these characteristics of May and suggesting that each might affect his credibility. I agree that in certain cases, such an instruction might be appropriate. But, I caution that our comments should not be construed to require the giving of such an instruction in this or any other case. The formulation of jury instructions is a matter within the discretion of the trial judge and, in my judgment, the majority’s suggestion should not circumscribe the exercise of that discretion.
It appears to me that we best carry out our appellate function by determining whether it was error to give or not to give a particular jury instruction in a particular case. Advice as to a “better practice” seems to me to be ordinarily outside our appellate responsibility. Prudence urges awaiting a concrete controversy on the particular issue.