Mr. Frazier.

The microscopic marks which were used in the identification, after being observed through the microscope and making the comparison and the identification; were photographed, and this photograph shows a portion of the surface of that bullet, showing parallel lines extending from the left side of the photograph coming up to the hairline and continuing across on the right side of the photo graph, these microscopic marks being very fine grooves and ridges on the surface of the bullet, very coarse ridges on the surface of the bullet, and in between size scratches left on the bullet by the barrel of the weapon.
There will be some marks which will not show up on one bullet which show up on the other bullet, and. similarly some marks on the other bullet, in this case Exhibit 399, will not be present on the test bullet, that situation being due to a number of causes.
One, the bullets could have originally been slightly different in diameter, the larger bullet, of course, picking up more marks during its passage through the barrel.
Secondly, the two bullets may not have expanded exactly the same, due to the pressure of the powder behind them as they passed through the barrel.
Third, with each bullet fired through the barrel, there are certain changes that occur due to the wearing away of the surface of the metal of the barrel, so that after a series of shots through a particular barrel, it would be expected that the pattern of microscopic marks produced by it would change.
The identification is based on areas such as this on the bullet and the comparison of the microscopic marks around the entire surface of the bullet which bears individual characteristics.

Mr. Eisenberg. Mr. Frazier, running through the middle of the exhibit there seem to be finer lines on the right- hand side than on the left. Could you explain that, the reason why the lines come out with more detail or that there are more lines on the right side than on the left?

Mr. Frazier.

Those marks could be the result of the bullet striking some object after it was fired, or they could be the result of changes having taken place in the barrel.
For instance, even a piece of coarse cloth, leather or some other object could have polished the surface of the metal slightly and left infinitesimal scratches which, when enlarged sufficiently, actually look like marks on the bullet.

Mr. Eisenberg.

In making your examination of the bullet, what was the relative attention you gave to the broader lines we see in this picture and the finer lines such as those we have just been referring to?

Mr. Frazier.

The broader lines would be more characteristic or they are looked for most, because they change less rapidly than the fine lines. For instance, firing two or three bullets through a barrel could completely erase microscopic marks which would appear as fine lines in a certain area, whereas the coarser lines and grooves on the bullet would be maintained over a series of fired bullets.

Mr. Eisenberg.

In evaluating these lines, do you examine the lines individually, or are you interested in their relationship with one another in addition?

Mr. Frazier.

It is a combination. You actually examine each mark and each line individually, but it is a mental process rather than a matter of adding one line to another. It is a process of looking at a series of lines and you actually notice that they are composed of round-topped ridges, V-topped ridges, flat-topped ridges, and it is a mental process of looking at the whole pattern rather than the individual marks.

Mr. Eisenberg.

All these lines that we are looking at lie within a groove, within one groove, did you say?

Mr. Frazier.

Yes; except for the lower portion of the photograph, there is a portion of a land impression showing one rather deep groove running across the bottom of the picture, and a series of grooves shown next to the edge of the land impression.

Mr. Eisenberg.

Will you identify the circular-looking mark on the right-hand side of the picture?

Mr. Frazier.

That could be either a flaw in the bullet, the metal itself, before it was fired, or could be the result of the bullet having struck some object after