Forensic imaging comes of age - includes related articles

FBI Law Enforcement Bulletin,The, Jan, 1994 by Gene O'Donnell

In 1987, the FBI's Newark, New Jersey, field office forwarded a then unusual request for forensic assistance to the Special Projects Section of the FBI Laboratory. Agents asked if it would be possible to produce age-enhanced photographs of a longtime fugitive in order to better represent to the public and to other investigative agencies how the subject might currently appear. The fugitive, John E. List, had eluded detection since murdering his entire family 17 years earlier.

Using newly acquired computer systems, visual information specialists in the FBI Laboratory prepared an age-enhanced image of John List and forwarded it to the field office. The office then publicized the photograph in various national publications. A woman recognized her neighbor as List (who lived under the assumed name Robert P. Clark) from the age-enhanced image that appeared in a supermarket tabloid. The woman dared Clark's wife to confront her husband with the photograph. Apparently, she never did.

Two years later, in 1989, the television show, America's Most Wanted, featured a plaster bust prepared by a forensic artist that was based on photographs of List. By this time, List had moved to Midlothian, Virginia, a suburb of Richmond. Convinced that Clark was, in fact, John List, his former neighbor asked her son-in-law to call the FBI and provide investigators with List's new address. When agents confronted the man, he denied he was List. But fingerprints from a gun permit application filed a month before the slayings revealed the truth. List was arrested and returned to New Jersey, where he was convicted of murder and sentenced to life in prison.

The John List case is notable for several reasons, including List's ability to elude detection for 17 years and the impact of mass media on his capture. For the FBI Laboratory, the List case also signaled a new age in computer-assisted forensic imaging.

BACKGROUND

Traditionally, forensic artists assisted investigators by producing drawings and airbrushed photographs based on witness accounts or photographs. Over the years, forensic artists produced many such images, which assisted in solving numerous cases. However, advances in computer technology now allow these same artists to create or alter images much faster, more accurately, and with many more options than ever before.

In 1986, the FBI purchased the computer system used for the age-enhancement of John List. Composed primarily of off-the-shelf hardware and software, the system allows operators to alter photographs for investigative purposes by projecting the likeness of individuals as they might currently appear. By combining the sophistication of the computer system with the forensic art skills of the operator, age-enhancement and other imaging can be achieved with a high degree of accuracy.

The programmer who developed the system used by the FBI worked closely with Laboratory personnel in making necessary modifications to enhance the computer's capabilities. The user-friendly format allows operators with limited computer training to make full use of the system. As always, the most critical element is the forensic art skills of the operators.

COMPUTER-ASSISTED FORENSIC IMAGING

The FBI's imaging program is based on a sophisticated photo compositing and retouching system. The system produces age-enhanced photographs, merged images (i.e., a human skull combined with antemortem photographs), and reconstructed facial images based solely on the skeletal remains. The forensic artist can also create detailed composite sketches on the system and use the system to perform other retouching functions.

In order to produce a desired image, forensic artists must generate several preliminary images. These initial and intermediate images, as well as the final product, are collected together in a folder referred to as a "film."

A film consists of several images, or "frames," in sequence. Each frame corresponds to one of the images used to produce the final product. To ease handling, the artist binds the frames together in a single film. This also ensures that all materials necessary to produce the final image can be found in a single place.

AGE ENHANCEMENT

The age-enhancement process begins by entering the images that will be used in an "update" into the computer system. Forensic artists enter these images into the system in several different ways.

In the most common method, the forensic artist uses the video camera to "grab" or digitize photographs into the system. This is accomplished by placing a photograph on a copy stand under an activated video camera to produce an image on the display monitor. When the photograph has been properly framed, the camera focused, and the lights adjusted, the image is "grabbed." The computer then converts the image into digital form and stores it in its memory. The forensic artist then repeats the image entry process for each reference image used in the aging process. When all of the photographs have been entered into the system, the forensic artist begins creating the aged image.