“The United States Marshals Service was established by Congress in 1789.”
The US Marshals are not a lot more than a tool of the federal court, congress, and the POTUS. They do not run as an independent organization with the purpose of investigations of the four groups they work for. That is not going to happen as it is not within their job description.
The FBI is a far more independent group with a far broader job description. You can find it on this site:
https://www.justice.gov/doj/organization-mission-and-functions-manual-federal-bureau-investigation
And one of their major tasks is in the first of the details with:
“Combat public corruption at all levels.”
This makes a far greater check and balance for criminal activity at all levels and inside the government itself. And that is what we need at this time and have since FDR in the early 30’s. Before that the government was a lot more transparent as now the government makes it appear that all the questionable stuff they get caught at is really okay or is caused by their opponents. The art of misdirection.
wy69