While grand juries have great leeway related to issuing subpoenas, the Fourth Amendment requires reasonableness. To meet the reasonableness standard, the subpoena must be likely to generate evidence that is: Relevant to the issue under consideration, be particular and reasonably specific, and be limited to a reasonable time frame. Relevant to the issue under consideration, be particular and reasonably specific, and be limited to class B felony (or higher) investigations. Relevant to the issue under consideration, be particular and reasonably specific, and be based on a higher than average probability that a crime has been committed Relevant to the issue under consideration, be particular and reasonably specific, and must meet the Daubert standard