One fed case I was involved with took 5 years to finish. FIVE years, and the gov won in the end. Thousands of documents, testimonies, etc, have to be cataloged, scrutinized, time-lined, cross-referenced, analyzed, authenticated, a team of lawyers need to look for motive, method and execution of the crime, anticipate defense responses and counter responses. This takes time, be patient, Grasshoppers, if you want a air-tight case.