Mr. Latona. Going from one extreme to the other, it may remain for years; under other circumstances, it may not even last for 15 or 20 minutes.
Representative Boggs. Why the difference?
Mr. Latona. Because of the amount of material which was left and the condition of the material which was left. Basically, the material may be made up of protein material and salt and water—primarily water. If it is totally water, with very little salt or oily material, when the evaporation is effected, then it is complete—there will be nothing left.
Representative Boggs. You mean that it is gone?
Mr. Latona. Right. On the other hand, if there is an oily matter there, we know that latent prints will last literally for years on certain objects.
Representative Boggs. Well, just for purposes of information, if I make fingerprints there on the table, how long would they normally last?
Mr. Latona. I don't know.
Representative Boggs. Well, would there be any way to know?
Mr. Latona. No, sir.
Mr. Dulles. It depends on temperature, on the amount of moisture involved?