Slight-Evidence Rule Law and Legal Definition

Slight evidence rule refers to a rule of evidence law that when evidence establishes the existence of a conspiracy between at least two other people, the prosecution need only offer slight evidence of a defendant's knowing participation or intentional involvement in the conspiracy to secure a conviction. The standard was set in the case Tomplain v. United States, 42 F.2d 202 (5th Cir. La. 1930). The rule was applied widely only after 1970 and since then it has been widely criticized. However, the rule is still followed in many jurisdictions.

Slight evidence rule also refers to the doctrine that only slight evidence of a defendant's participation in a conspiracy need be offered for admitting a coconspirator's out-of-court statement under the coconspirator exception to the hearsay rule. This rule is codified at USCS Fed Rules Evid R 801(d)(2)(E) which says a statement is not hearsay if it is a statement by a coconspirator of a party during the course and in furtherance of the conspiracy.