Part of the National Archives and Record Administration’s duty is to provide the public with access to its billions of pages of texts, maps, photos, film, and other artifacts of American history—but some of them aren’t so easy to view. The bullets from John F. Kennedy's assassination, for example, have long been considered too fragile for anything but sitting in a climate-controlled vault in Washington, D.C.

However, they recently took a field trip to the National Institute of Standards and Technology (NIST) in Gaithersburg, Maryland, where the ballistics team there used advanced microscopic imaging techniques to create breathtakingly accurate 3D digital replicas.

NIST

According to a press release from NIST, the collection includes two fragments from the bullet that killed Kennedy, the so-called “stretcher bullet” that hit both Kennedy and then-governor of Texas, John Connally; two bullets from a test-fire of the assassin's rifle, and a bullet from an earlier unsuccessful assassination attempt on Army Major General Edwin Walker that might have come from the same rifle.

As you can probably imagine, the two fragments from Kennedy’s fatal bullet are the most affecting pieces of the collection. They also give you a pretty good understanding of how difficult it must have been to recreate them—the bits of metal are twisted into gnarled, asymmetrical shapes that look different from every angle.

NIST

To replicate each miniscule mark, ridge, and divot, NIST physical scientists Thomas Brian Renegar and Mike Stocker spent hours rotating the artifacts beneath the microscope, capturing images from all perspectives, and then combining parts of the images to create full 3D versions of them.

“It was like solving a super-complicated 3D puzzle,” Renegar said in the release. “I’ve stared at them so much I can draw them from memory.”

Kennedy’s assassination on November 22, 1963, has generated no small number of conspiracy theories over the years, but NIST and the National Archives made it clear that the project to replicate the bullets was “strictly a matter of historic preservation,” and not in any way a reopening of the case. But once the complete 3D scans are made available in the National Archives’ online catalog in early 2020, members of the public are free to analyze them however they like.

“The virtual artifacts are as close as possible to the real things,” Martha Murphy, the National Archives’ deputy director of government information services, said in the release. “In some respects, they are better than the originals in that you can zoom in to see microscopic details.”

And while Kennedy’s case is closed, the cutting-edge technology used on his bullets will be used in the future.

“The techniques we developed to image those artifacts will be useful in criminal cases that involve similarly challenging evidence,” NIST forensic firearms expert Robert Thompson said in the release.