The halls of Congress certainly don't look like the halls of Congress these days. They look like a dump.

New members are moving in. Old members are moving out. Lots of people are switching offices.

Bags of trash and furniture line the halls. Gigantic trash bins brim with old papers, binders and files.

Spring cleaning comes every other fall here on Capitol Hill.

In the basement of the Cannon House Office Building, maintenance teams have set up what's billed as an "Office Re-Supply Location." 

This is where aides can "pick up stuff" and "drop off stuff."

Everything is free for the taking.

Staffers can cruise by to check what's available.

"And people go right to the supply store to buy the same things," said one aide. "You could come here and save money."

A chart stands nearby asking people to list what they've dropped off and what they've claimed.

Here's what's available: An unopened packet of pink message slips, a pack of Bic Round Stic pens, a box of Sylvania light bulbs, even a black file tray with slots for incoming messages for each aide. The shelves already bear names: Colleen!, Daniel, John, Laura, Carmen. 

No explanation is given why Colleen! gets an exclamation point. Perhaps she always forgot to check her messages. A sticker is pasted to the back of the tray.

It reads: "Let's Welcome Puerto Rico as the 51st State!"

Perhaps the tray belonged to Puerto Rico's non-voting resident commissioner in Congress, Republican Luis Fortuno. He's leaving Washington to become to become the territory's governor.

Items that people claimed -- A box of matches, folders, and as one aide scribbled on the sign-out sheet, large rotary cards with a "whole" puncher.

Criminal investigators have long sorted through trash as a way to piece together information. They determine where people shop, whether they brush with Crest or Colgate. Gin bottles could give off all sorts of signals.

And much like investigators learning a lot about their subjects, a lot can be gleaned about Members of Congress and their aides by just seeing what they casually cast aside in the hall.

A collection of eight lamps rests outside 514 Cannon. Rep. David Davis, R-Tenn, is vacating that office after he lost in his primary.

An empty picture frame rests against the door of Delegate Madeleine Bordallo, D-Guam. It bears the request, "Please to not remove."

Down the hall, the staff of Rep. Randy Neugebauer, R-Texas, took a more direct approach when it came to its claim for a swivel office chair.

"Absolutely do not remove!" warned a hand-scribbled sign affixed to the chair.

They attach these signs because of something known as the "Law of the Hall." The Law of the Hall is a rule of the jungle. If something is left there for more than an hour, someone else can claim it. It doesn't matter what it is. File cabinet. Furniture. Telephone. Lamborghini Murcielago.

That changed in the mid-1990s when then the House began bar-coding and assigning furnishings to offices.

But that doesn't mean the Law of the Hall doesn't rule still.

Randomly lying on the fourth floor of Cannon are two maps outlining the boundaries of "Rep. Rob Portman's Congressional District" in southwestern Ohio.

Portman hasn't served in Congress since early 2005, when he left to become U.S. Trade Representative and then White House budget director. Rep. Jean Schmidt, R-Ohio, succeeded Portman. But it doesn't explain the randomness of his map lying unsalvaged in a congressional hallway.

Interesting findings are available near the office of defeated Rep. Nick Lampson, D-Texas. At the top of a trash bin rests a huge, unopened cardboard box. Its label indicates the box holds 500 pocket-sized versions of the Constitution.

By ditching the otherwise mint-condition Constitutions, perhaps Lampson is taking out his frustration on Article 1, Section 2. It states that House members will be "chosen every second year."

Lampson lost his seat in 2004, won it back in 2006 and then lost this year to Republican Pete Olsen.

Abandoned in one corridor are two garbage bags filled with shredded documents. Another office deposited an actual paper shredder in the hall. But seemingly the staff of one congressman from the Plains could have used that shredder.

Lying on the floor were dozens of folders housing the employment action forms for various aides as well as photocopies of driver's licenses and Social Security cards. They belong to everyone from interns to chiefs of staff.

This is just stuff discarded on the floor. A less scrupulous type might find use for that information, say a petty criminal, an Al Qaeda operative or a foreign government interested in blackmail.

It's a veritable treasure trove all deposited aimlessly here in the very public hallways of Congress.