While most state cases are initiated quickly after a suspected crime occurs, federal cases may be investigated months or even years before any individuals are arrested.
Federal agents use a variety of techniques to gather information, including surveillance, wiretapping or analyzing financial documents. There is also often extensive interaction between targets and law enforcement officials. It’s not uncommon for agents to knock on a target’s door out of the blue and ask questions. They will often couch their request for an interview by saying they are just inquiring or seeking information for benign purposes.
In reality, agents are seeking to develop evidence against a target in a pending investigation. Here’s an overview of the stages of a federal criminal case and an explanation of each step, starting with the filing of a criminal complaint through sentencing: