Remember that Seinfeld episode, where Jerry had the overdue library book, and he was being investigated by Lieutenant Bookman, the library investigation officer? While that's not real, you'll feel just like Jerry when you find out there's some law enforcement branches of some stuff that you wouldn't think would need it.

10. The United States Postal Inspection Service

The USPIS is the federal law enforcement arm of the Postal Service, and they're one of the oldest law enforcement agencies in the country - dating back to 1772. They originally were made to protect postal operations during the Revolutionary War. Since, they handle postal-related crimes, including mail fraud, identity theft, cyber fraud, narcotics trafficking and financial crimes.

9. Bureau of Reclamation’s Security Response Force

The tactical unit within the U.S. Department of the Interior is the specialised force that ensures the uninterrupted operation of dams, reservoirs and hydroelectric power plants. Don't screw around at the Hoover Dam, Grand Coulee Dam or Glen Canyon Dam, or you're going to find out who these guys are.

8. United States Coast Guard Police Department

These guys are basically the MP's of the Coast Guard.

They've got the Maritime Safety and Security Teams (MSSTs) and Deployable Specialized Forces (DSF) in broader security operations. Their responsibilities ensure Coast Guard facilities remain safe and mission-ready.

7. United States Forest Service Law Enforcement and Investigations

The USFS LEI serves as the enforcement branch of the Forest Service as well as the Department of Agriculture. They protect all the 193 million acres of the National Forests, natural resources, wildlife, and recreational areas. They patrol the remote wilderness areas.

They've got some pretty broad jobs - keeping an eye out for illegal logging, poaching, arson, drug production (such as illegal marijuana grows), and other environmental violations, but they also cover campgrounds, hiking trails, and forest infrastructure.

6. NASA Protective Services Division

Pretty plain and simple, these guys oversee the protection of research centers, spaceflight facilities and high-security installations. They've got some fancier teams like Emergency Response Teams (ERTs) or Tactical Response Teams (TRTs), which function similarly to SWAT units, which they use to stop active shooter situations, terrorist threats and espionage concerns.

The NASAPSD work alongside the FBI, DHS, and DoD often.

5. New York City Taxi and Limousine Commission Enforcement Division

This TLC isn't about chasing waterfalls, but they will pick up some scrubs. These guys go out and enforce transportation laws and regulations governing taxis, limousines, and for-hire vehicles (FHV) such as Uber and Lyft. They make sure everyone from the business owners down to the drivers are in compliance with the passenger safety laws.

TLC officers are not sworn NYPD police officers but peace officers with specialized enforcement powers.

4. Department of Energy (DOE) Security Police Officers

These are the guys who safeguard the nuclear weapons, radioactive materials and classified energy research at Department of Energy sites. They're the big guys hanging around the national labs, and they're no joke. These guys train for some big-time scenarios, as well as being the first response in radiation-related emergencies in the facilities.

3. United States Mint Police

These guys' name pretty much tells you what they oversee: The US Mint. The place that everyone would love to rob probably has one of the biggest and most badass response teams. U.S. Mint facilities, employees, and billions of dollars in gold, silver and coinage are all under their jurisdiction.

When people say "It's locked up like Fort Knox," that's these guys.

2. Bureau of Engraving and Printing Police

Now this is a weird one. Under the Department of the Treasury, these are the guys who protect the plates that they use to make the money.

1. Amtrak Police Department

This one's pretty self explanatory as well, but it's crazy they've got their own police. I suppose it's like the TSA, only on a train. They've got the power to arrest, investigate crimes, and conduct security operations in and around Amtrak stations, rail yards and onboard trains.

Seems like a lot, but this is the only mode of travel that still doesn't have you arrive an hour and half early to get through security. Nope, just show up and get on the train, we'll figure out if you've got a ticket down the way.

LOOK: Iconic products released the year you were born

American history can often be remembered through our consumer habits. That's why Stacker ranked the iconic products released from the year you were born, starting in 1919. From Slurpees to iPods, this list is a pop culture-infused trip down memory lane.

Gallery Credit: Stacker

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