Fire Marshals over the years had the power to legally remove evidence or even seize business records from a property without the need of a signed court order since they were able to write their own subpoenas.
Back in the 80's the bureau had over 350 members. Cut backs has caused the bureau to be downsized in recent years. Their Citywide North Base
has recently been reopened to cover Queens, The Bronx, & Northern Manhattan. Their most famous group were the "RED CAPS".
The Marshals are broken down into bases subdivided into Squads. The base has an assigned commander & maybe an assistand base commander. Then the next lower subdivisions are the 'Squad'. This is a work group & also can be a subdivision of that group. Two marshals make up a team but on the radio they are called "Squad 31 Adam, Boy, or Charlie" & so on. The Supervising Fire Marshal for that Squad (work group) would be "Squad 31".
Over the years they did provide 24-hour coverage from the borough bases, not sure about now.
However, they have had many unmarked undercover vehicles in the past that I had knowledge of.