Yes I understand, police can assist Marshals will warrants and many of the other things listed. It was just an idea for another job. Also, USMS is a federal law enforcement agency within the U.S Department of Justice. So essentially, it's not a branch of "Police". The USMS also have a Special Response Team which deal with High Risk arrests, and many other Special Law Enforcement Operations. USMS are a lot bigger than they seem, the Marshals are responsible for over 55.2% of arrests of federal fugitives, also in 2012 the Marshals captured over 36,000 federal fugitives, and cleared over 39,000 fugitive warrants. The Marshals arrest around 336 fugitives every day on average.