In the Green v. Bock Laundry Machine Co., 1988 case, the U.S Supreme Court ruled that Federal Rule of Evidence 609(a)(1) should be interpreted to favor plaintiffs in civil cases. The rule allows for a witness's credibility to be impeached by evidence of a criminal conviction if its probative value outweighs its prejudicial effect on substantive issues. In this case, Charles R. Green was injured while working with a laundry press manufactured by Bock Laundry Machine Company and sued them for negligence and strict liability. He had prior felony convictions which were revealed during trial despite his objections, leading to an unfavorable verdict from the jury against him. Green appealed arguing that revealing his past convictions unfairly influenced the jury’s decision against him because their prejudice towards his character overshadowed any consideration of whether he was actually harmed due to negligence or not. The Supreme Court agreed with Green stating that when determining whether evidence is more prejudicial than probative under Rule 609(a)(1), courts must consider it from perspective of defendant (in this context - plaintiff). Therefore, they held that lower court erred in allowing introduction of such evidence without properly weighing potential prejudice.

In the dissenting opinion for Green v. Bock Laundry Machine Co., Justice Blackmun, joined by Justices Brennan and Marshall, argued that Rule 609(a)(1) of the Federal Rules of Evidence should be interpreted to allow impeachment of a civil defendant with prior felony convictions only when its probative value outweighs its prejudicial effect on substantive issues. They disagreed with the majority's interpretation which favored defendants over plaintiffs in civil cases. The dissenters believed this was inconsistent with both the language and purpose of Rule 609(a)(1). They also criticized the majority’s reliance on legislative history as they felt it was selective and misleading. Furthermore, they contended that even if there were ambiguity in interpreting Rule 609(a)(1), any doubts should be resolved in favor of treating all parties equally rather than giving preferential treatment to one party over another.