impressions of the finger joints. Persons not
experienced in latent print comparisons should not attempt to evaluate
latent fragments, since the area necessary for an identification may
be extremely small compared to that of an average inked fingerprint.

Articles which are to be transported by mail or express should be so
packed that the surfaces bearing latent impressions are not in contact
with other surfaces. This may be accomplished by mounting the articles
on a piece of fiber board or plywood. The board should then be secured
in a box so that the objects will not touch or be shaken against the
sides in transit. The package should be plainly marked "Evidence," to
prevent inadvertent handling on opening. Cotton or cloth should never
be placed in direct contact with any surface bearing latent prints.

Any number of paper or cardboard specimens may be placed in a single
protective wrapper, since contact with other surfaces does not harm
latents on such objects. Lifts, negatives and photographs are readily
enclosed with letters.

An explanatory letter should accompany all evidence. If it is
necessary to pack the evidence separately, a copy of the letter should
be placed in every package so that the recipient will know immediately
the import of the contents. All items of evidence should be marked and
described exactly in the accompanying letter so that they will not be
confused with packing material of a similar nature, and to provide a
check on what the package should contain.

In addition, the letter should include for record purposes a brief
outline of the crime, i.e., type, date and place of occurrence, and
names of victims and subjects. If suspects are named for comparison,
sufficient descriptive data should be set out to permit location of
their fingerprint records. This information, in preferential order,
comprises the individual's complete name, aliases, FBI number, date of
prior arrest or fingerprinting, fingerprint classification, date and
place of birth, and physical description.

Evidence is preferably forwarded by registered mail or railway
express, as these means provide records of dispatch and receipt.

Elimination or suspect fingerprints are best enclosed with the
evidence itself, with a notation as to the type of prints forwarded.

CHAPTER XIII

_Powdering and Lifting Latent Impressions_

The sole purpose in "developing" a latent impression is to make it
visible so that it may be pres