If you or a friend are possibly facing this you should lawyer up as soon as possible, the feds are no joke.
My name is Stephen R. Cohen and have practiced since 1974. I practice in Los Angeles and Orange County, CA. These answers do not create an attorney client relationship. My answers may offend I believe in telling the truth, I use common sense as well as the law. Other state's laws may differ.. There are a lot of really good attorneys on this site, I will do limited appearances which are preparation of court documents it is , less expensive. However generally I believe an attorney is better than none.
The investigations and the prosecutions can be sequential or concurrent dependent on multiple factors. They are usually cooperative in sharing leads and witness.
Of course, every answer or response is based on the information provided in the question asked and requires a much more complete context than is available in this public forum. This answer/response should NOT be relied upon to make any legal decisions. Seek the advice of an experienced Federal and/or state criminal defense attorney in your jurisdiction BEFORE you say or do anything.
The simple answer is that the investigation will be ongoing in all jurisdictions. If crimes were committed in multiple districts or jurisdictions the Feds tend to coordinate with each other very well. They will share information with each other, coordinate with each other, and generally work together. Crimes may be charged in the jurisdiction where they occur and can be later consolidated/ transferred to one jurisdiction for judicial economy and ease of prosecution.
This can happen in many different ways. I recently tried a Federal drug case where the DEA in San Diego passed on information from their investigation to the DEA in Tampa. That information ultimately was combined with what Tampa knew for a prosecution effort in the Middle District of Florida. This would be an example of a multi district investigation that led to a prosecution. I've been consulted in Wire Fraud cases where there are criminal allegations in more than one district for different but similar acts. In some instances where one has been convicted and then is released on supervised release, if they are indicted in a different district the supervised release will be revoked. Regardless of whether the multi district activity is at the investigatory stage or a prosecution stage you can bet the Feds will know of all of it and will share what they have.