TULSA, Oklahoma - A team from the Library of Congress is at Tulsa's Gilcrease Museum examining historical documents including the Declaration of Independence.

It's the only remaining handwritten copy of the document.

They will be looking at a fingerprint they found in the ink, trying to determine who it belongs to. They haven't identified the fingerprint yet.

Friday, the experts went through one of the first steps in identifying the print. The Library of Congress will do hyperspectral imaging first. Once they have the images, they can examine the print.

Hyperspectral imaging is an advanced type of photography which can see under layers of ink.

"With this system, they are able to gain more information from an object that before, they were only able to see with the naked eye," said imaging specialist Michael Toth.

Several other documents are also being looked at including the Articles of Confederation and letters from Thomas Jefferson and Benjamin Franklin.

They expect to have the fingerprint identified by the end of March.