Modern document examiners not only determine authorship and authenticity but they use the latest technology to detect changes, resurrect evidence, recover entire documents, and analyze DNA. 

This article is the second and final part of a series on forensic document evidence, which can be found in virtually every fraud investigation. Adapted from a presentation at the ACFE's 13th Annual Fraud Conference, the authors developed it in close cooperation with the Miami-Dade (Florida) Police Department Crime Laboratory. - ed. 

In the January/February issue, we discussed traditional questioned document examinations including methods of handling documentary evidence and selecting a qualified document examiner. Modern document examiners have broad abilities beyond the traditional authorship and authenticity determinations. They can, for example:

• detect alterations, erasures, and obliterations;
• resurrect evidence deteriorated by fading or decomposition; and
• recover entire documents, or portions of documents, from underlying pages, which were present when the original document was written.

Document examiners use such equipment as the Video Spectral Comparator, Raman Spectral Comparator, and Electrostatic Detection Apparatus.

Video Spectral Comparator

Ink fluoresces under certain ranges of light, which are invisible to the naked eye. The Video Spectral Comparator (VSC) uses filters to vary the light bombarding the document. The document is viewed through a camera and computer monitor. As the wavelength of the light is varied, the picture changes.

When a subject makes an alteration on a document he often uses a different pen from his original writing. Varying inks may appear to be the same color to the naked eye or even under magnification. But they will fluoresce differently and reveal two writing samples made with two different pens at two different times.

Fluorescence is also used to detect deteriorated, obscure, indecipherable, or invisible evidence. In one landmark case, the Miami-Dade Police Department Crime Laboratory was able to recover a telephone number written on a murder victim's palm. (See Exhibits 1 and 2.) The number could not be read with the naked eye or with magnification, but it fluoresced under the VSC. When investigators went to the address to which the number was traced, the murderer opened the door and confessed.

[Exhibits 1 and 2 are no longer available. — Ed.]

Raman Spectral Comparator

The Raman Spectral Comparator (RSC) is similar to the VSC but with two important differences. The RSC bombards the target with laser light instead of light waves. Also, the RSC output is a graphical depiction of the exact chemical composition of the object targeted by the laser rather than a visual image. This process is chromatography and the graphical output is a spectrum. (See Exhibit 3.) Chromatographic analysis is highly specific because it shows the exact components and strengths of each chemical element in the sample. Spectra can be digitized and stored in databases for future comparisons with other unknown substances or for comparison with spectra of known substances. RSC analysis is applicable not only to inks but also to papers, dyes, etc.

[Exhibit 3 is no longer available. — Ed.]

Electrostatic Detection Apparatus

The Electrostatic Detection Apparatus (ESDA), which forensic scientists have used for many years, operates somewhat like a photocopier. Originally designed to develop latent fingerprints from documents, the ESDA is normally used to recover invisible indented writings. (See Exhibit 4.)

Here is one case in which the ESDA discovered a doctor's ethical slip. During a patient's examination, the doctor wrote his evaluation on the patient's chart and verbally advised surgery. Unfortunately, the patient did not survive the surgery. Fearing a malpractice suit, the doctor removed the page on the patient's chart and wrote on it, "I recommend against the operation," and returned the page to the chart. (See Exhibit 5.) The doctor made the alteration with the same pen he used in the earlier notations so a VSC examination under various light wavelengths did not reveal anything unusual. (See Exhibit 6.)

[Exhibits 4, 5 and 6 are no longer available. — Ed.]

However, the document examiner used the EDSA to inspect the pages under the one the doctor altered in the patient's chart. The EDSA applied an electrostatic charge to the paper and then the examiner placed a vinyl sheet - covered with a toner-like material - next to the document. The toner collected in invisible indentations in the vinyl sheet and the writing from the page above appeared.

All of the doctor's original notes were visible, but the sentence, "I recommend against the operation," did not appear. (See Exhibit 7.) It is obvious the doctor added the phony sentence after the fact.

[Exhibit 7 is no longer available. — Ed.]

'Star Wars' Evidence from Documents  

There are least two other important types of evidence that can be developed readily from many documents: fingerprints and DNA. Though examiners have scrutinized both for years they now have "Stars Wars" methods to do the job.

Fingerprint Evidence

Fingerprints can be patent, such as visible greasy or bloody handprints, or latent, such as invisible prints left behind by the natural oils on fingerprint ridges. In police mythology of the mid-1970s, latent fingerprints could easily be found if they were left on dry, smooth, hard surfaces but not on paper, which is porous and absorbent. A crime scene investigator's classic dream was a suspect's fingerprints found on a Formica countertop of a local convenience store that had just been robbed.

Fingerprint dusting does not work on documents because paper absorbs skin oils. However, ninhydrin spray, a reddish chemical reagent, adheres beautifully to fingerprints on paper or anything else. Unfortunately, the chemical is toxic and messy, turns the paper purple, and obscures any writing. Obviously, document examination must precede fingerprint processing.

Document examiners also employ polymer fuming using Superglue™. The examiner places the object in a container and drips a small amount of Superglue™ into the container and closes it. As the Superglue evaporates, the fumes adhere to the oils and leave a white image of the fingerprint.

DNA

Documents yield not only fingerprint evidence but, thanks to high-tech advances, a fraudster's dioxyribo nucleic acid (DNA) can be detected. DNA is the genetic key to our individuality. DNA matching has been used for decades to determine paternity. But in the United States, it was not until the late 1980s that law enforcement began using DNA evidence, and only for the most notorious cases because of the high cost.

But now DNA testing technology has been refined so that unknown rapists are being uncovered by computer databases without any other clues to their identities. And many criminals professing innocence are demanding - and often suing to obtain - DNA analysis to clear them of crimes for which they have already been convicted.

With improved technology, crime-scene contamination is a non-issue; it is now simple to differentiate DNAs. Forensic scientists once needed a quarter-size sample to attempt analysis. Now they can obtain and analyze invisible microscopic samples. They use Polymerase Chain Reaction (PCR) to replicate even a miniscule amount of DNA into sufficient quantities of evidence for complete testing. As a hypothetical example, assume some crackpot wanted to send an anthrax hoax letter to some organization he did not like. The two most obvious places to look for DNA would the adhesive on the envelope and the stamp, which the suspect licked. Investigators could also look for dead skin cells ("slough cells") rubbed off on the letter.

The examiner does not have a problem discovering DNA evidence but often cannot find the right suspect to compare with the evidence. Most American states maintain computer databases of sexual offenders' and violent felons' DNA information, and many states now are moving toward DNA sample collection in all felony cases. However, detectives and uniform patrol officers now also are routinely collecting DNA samples in the field. They compare these samples against databases of open case evidence and often have startling results. The Miami-Dade Police Department DNA Unit typically makes five to six "blind" identifications per month and recently made 11 in one week.

They also find frequent identifications by comparing unsolved, cold cases with databases. (In what may be the ultimate irony, jailed criminals - who hope to exonerate themselves - sometimes not only prove their guilt for the crimes for which they are imprisoned but unwittingly identify themselves as the perpetrators of previously unsolved cases.)

Knowing forensic document methods and technology will allow the professional to go far beyond the intellectual content and visible physical evidence found on a document. The well-trained CFE knows there is a lot more than meets the naked eye.

James D. Cooner, CFE, is president of Aspen Consulting Group in Miami, Fla. Harry Coleman is a Questioned Document Examiner in the Miami-Dade (Fla.) Police Department Crime Laboratory.  

The authors wish to thank these colleagues for their advice and assistance in preparing this article: Commander James Carr of the Miami-Dade (Fla.) Police Department Crime Laboratory Bureau; and Supervisor "Bud" Stuver, Michael Haas, Ph.D., Toby Wolson, and Stephanie Stoiloff of the crime laboratory's Serology/DNA Section.

How Can I Identify Thee? Let Me Count the Ways

In a recent case, a woman's body was found abandoned. She had been strangled and a cord was still around her neck. Her car had been stolen but was later recovered several hundred miles away. The driver of the stolen car was arrested for auto theft.

An empty soft drink can was found in the car along with the victim's belongings. The arrested driver's DNA was identified on the steering wheel of the car, on the rim of the soft drink can, under the fingernails of the victim, and on the ends of the cord he had used to strangle the victim.