Library of Congress


The Library of Congress > Teachers > Classroom Materials > Presentations and Activities > Historical Detective
City Detectives group, June 8, 1913

[Detail] City Detectives group, June 8, 1913

Search American Memory collections to test your D.Q.
(Detective Quotient)!

True or False? Was Billy the Kid really killed by Pat Garrett at Fort Sumner, New Mexico?

What evidence can you find to prove your answer? Are there any conflicting accounts of his death? Are there any conflicting accounts of his life?


Solving a riddle or puzzle is the same whether you are doing your detective work on the eighteenth century or the twentieth century.

  • You must ask questions (who? what? when? where? why? how?), hunt for clues, talk to witnesses and visit the scene to search for evidence.
  • You must form a hypothesis (I think ...... because .......) and gather evidence to prove your hypothesis.
  • Your evidence must be authentic, first-hand information that you have carefully reviewed to make certain that it is genuine and will prove your hypothesis.
  • Occasionally your investigation will uncover vital facts that will make you rethink your original hypothesis and make the necessary changes to solve your riddle or prove your case.


  • What are your keywords? (Remember that the Library's search tool can search on subject terms and words in the photograph's caption in the bibliographic record of the item.).
  • What collections have these keywords? View the list of collections. Select “Show Selection Descriptions.” This may aid your search.
  • Brainstorm words. Check your spelling (remember - YOU are the detective, not the computer).
  • At a dead end? Use the alphabetical subject listing in each collection to give you some ideas. Scan the list to see what kinds of clues you can find.
  • Try your keywords in the search box of the American Memory Collection Search Page or on the search page of individual collections.
  • Need help? Ask your school media specialist or teacher. You can also send a message to our Reference Librarian. Select the “Contact” link at the bottom of every Library Web page, then select “Ask a Librarian.”
  • Gather evidence. What is your hypothesis?
  • Was your hypothesis complete? Did you find other forms of evidence that caused you to restate your original hypothesis?


If you are really ready to check your hypothesis, you can find the answer to the mystery here.