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Fingerprint Expert  What They Do

Just the Facts

Insider Info

dotMost fingerprint analysts work on the mundane aspects of police work -- they locate fingerprints (latents) at the site of armed robberies or residential break-ins.

But they also work on homicide cases. That means they have to search the premises for prints. They may also have to take prints from the deceased in order to make an identification.

dotSmooth surfaces produce the best prints, so analysts examine door handles and window and door frames. While a complete print is the ideal find, partial prints can also be identified. Some criminals even have footprints on file, so a print in blood can't be overlooked.

dotA fingerprint analyst uses a variety of powders to dust surfaces -- light colored powder on dark surfaces and dark powder for light surfaces. The prints are "lifted" off with the aid of sticky tape and then transferred to paper.

Everything must be preserved in pristine condition in anticipation of a future court case -- right down to the sticky tape itself, which will prove any future match is legitimate.

The fingerprint is then brought to a lab and matched to a file of known local criminals. If no match turns up, analysts search the international fingerprint database -- an automated fingerprint identification system -- to locate the print. If there's a match, then the original and the print from the database are placed side-by-side and entered as an exhibit during trial.

The analyst can be called by either the prosecution or the defense and must be able to convince the jury of their findings. A fingerprint can make or break a case.

dotNot all fingerprint analysts are police officers. In the U.S., analysts are usually civilians. Whether they attend the crime scene or not varies from one agency to another.

dotAmerican police departments are notoriously understaffed. Donna Jewett is supervisor of the central identification unit at the San Jose Police Department. She is also chair of the International Association of Identification's (IAI) fingerprint analysis committee.

"We have a tremendous shortage," says Jewett. "They're recruiting at the college level."

The big problem for Jewett is finding people with the training. With California's high cost of living, few experienced people are willing to transfer. Instead, she has to find people capable enough to put through training.

"For entry-level positions, we usually take people from the records department because they have some background knowledge."

At a Glance

Trace criminals' fingerprints

  • Many of these experts are employed by police departments
  • You may have to testify in court
  • Your work can make or break a case