Research was conducted by fingerprint specialists at the Bureau of Alcohol, Tobacco and Firearms (ATF) San Francisco Laboratory Center (SFLC). Using nine randomly selected firearms at the SFLC, on fingerprint processing using vacuum and atmospheric cyanoacrylate fuming. Particular interest was paid to what the fumed latent prints looked like prior to any enhancements. Test prints were placed on various surfaces of the nine firearms. The firearms were not wiped down prior to the placing of the test prints. Both the test prints and previously left latent prints were tested. The firearms were stored at room temperature for a 24 hour period prior to testing. After each test, the firearms were examined using a fluorescent room light and a magnifying class. The test prints were studied and estimates were made on the visibility and ridge detail. Several conclusions were drawn from this limited study. First, previous research was confirmed on latent print visibility. Second, vacuum processing did not appear to over develop fingerprint evidence on blue steel surfaces. Third, almost none of the test or pre-existing latent prints were enhanced after the second vacuum fuming which was a desirable outcome. And, lastly, only one pre-existing latent print of value was recovered from the nine firearms. The vacuum cyanoacrylate fuming method of latent print processing was demonstrated to work well on firearms and may be the method of choice for blue-steel firearms. Atmospheric cyanoacrylate fuming serves as an efficient way to enhance latent prints developed by vacuum fuming and the method of choice for polished light-colored finishes. References, tables