FORENSIC IMAGING COMES OF AGE

                   FORENSIC IMAGING COMES OF AGE

                               By

                         Gene O'Donnell

                  Visual Information Specialist

                    Special Projects Section

     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.

     The computer displays available commands in a collection of

pop-up menus driven by a fixed menu selection that runs across    

the bottom of the screen. The operator selects a category by

pointing to it with a pen-shaped stylus. Once the operator makes

a selection, the list of commands in that category appears in a

pop-up menu. The operator alters the image by selecting different

commands from the various menus and then drawing on the image

using the stylus. Mistakes can be corrected through a variety of

commands.

Child Aging

     When "aging" childhood photographs, forensic artists can

develop highly accurate and detailed enhancements by studying

photographs of the subjects' family members to gauge accurate

facial growth patterns. Since the introduction of the

computer-assisted system, the FBI Laboratory has assisted in

locating several missing persons, based solely or in part, on

this investigative technique.

     To update a child's appearance, the forensic artist enters

photos of the child, as well as one or both parents (or siblings

who resemble the child) into the computer. The operator then

creates grids for each image that "describe" the location of the

facial features in that image. One or more of the missing child's

photographs are "warped" or realigned to bring the features of

that image into alignment with those of another.

     After this process, the images can be composited (or

combined). The result represents the aged image because warping

simulates the growth of the child's face. The percentages of the

images to be composited can also be adjusted to emphasize one

image or another. By adjusting these percentages, as well as the

degree of warping, the artist determines the "age" of the

resulting image. Retouching capabilities allow for various

hairstyles or the removal of blemishes.

     When deciding on what photographs to combine with the

child's image, investigators should look for similarity of

features in the photographs of the relatives taken at

approximately the same age as the missing child. However, in

photographs to be used in the update, relatives must be as close

as possible to the age the child would be currently. The position

of the heads in the photographs of the child and the relatives

must match closely. Facial expressions should also match.

Ideally, photographs should be evenly lit and of high quality.

Adult Aging

     The aging of an adult subject works in a very similar manner

to the updating process for a child. The primary difference lies

in the use of an age template that is combined with the image to

be aged. The artist modifies the template to fit the features of

the image.

     Because cranial growth is complete in adults, the artist

gives special attention to preparing an accurate depiction of the

skin surface, adding necessary creases around the eyes, forehead,

and other appropriate areas. Indications of hair loss in earlier

photos or information from witnesses may lead the artist to

remove hair or make other changes, such as adding a beard or a

scar or adjusting the weight of the face.

     As with the updating of a child's image, any photographs

that are to be combined must be in similar orientations--

preferably head-on shots. Slight deviations from this full-face

angle can be compensated for during the warping process, but some

distortion may result. If the deviation is too great, another

image should be used.

SUPERIMPOSITION

     Forensic laboratories often receive requests for assistance

in cases that require the comparison of an antemortem photograph

with a recovered cranium and mandible (jaw bone). The computer-

assisted system for photographic superimposition offers a highly

effective method to demonstrate consistency (or inconsistency)

between skeletal features and facial photographs.

     First, the antemortem photograph is scanned with a video

camera and then digitized and stored in the computer. The artist

traces key anatomical "landmarks" directly onto a plastic overlay

on the monitor. The image of the photograph is removed from the

monitor, and the image of the cranium and articulated mandible is

oriented manually until the position approximates that of the

individual in the photograph.

     The image of the photograph and the image of the cranium/    

mandible are then merged or superimposed to allow detailed

comparison. The artist stores the superimposed images and prints

them on high-resolution printers. Accurate comparison requires

the combined efforts of a skilled forensic artist and an

experienced forensic anthropologist.

FACIAL REPRODUCTIONS

     When investigators find human skeletal remains with few

clues as to their identities, forensic scientists, artists, and

anthropologists often attempt to recreate the images of the

individual from the skeletal remains. In the past,

two-dimensional drawings and three-dimensional reproductions of

the remains--with clay added directly to the cranium to simulate

anatomical features--produced helpful leads for investigators.

     In recent years, facial reproduction has become an

increasingly important tool within forensic anthropology to

identify missing persons. While the technique is of little value

for purposes of positive identification, it can be extremely

useful in presenting an image to the public.

     In computer-assisted facial reproduction, the cranium and

articulated mandible are positioned in what is called the

Frankfort horizontal plane (a scientific articulation of the

cranium and mandible for photographing the cranium) and scanned

with the camera. The artist selects features and adds them to the

captured cranial image. The artist and the anthropologist then

modify the features until a lifelike image conforming to the

proportions of the underlying cranium is produced. In the FBI

Laboratory, facial components are selected from a large database

of handdrawings that depict wide variations in facial features,

complexions, and hairstyles.

COMPOSITE SKETCHES

     For many years, investigators have sought the assistance of

forensic artists in yet another area of forensic imaging-

composite sketching. FBI use of such drawings dates back to 1920;

use in other agencies dates back even further. Television

programs often depict a police composite artist at the bedside of

a victim, quickly sketching a portrait of an unknown assailant.

While real-world forensic artists often produce portrait-style

drawings, these images generally require hours of interviewing,

drawing, and revision.

     The FBI has converted its book of photographs used for

interviewing witnesses for composites into handdrawn images to

use as a database on a computer that will automatically generate

images similar to those that are handdrawn. Once the witness

selects features from the catalog, the composite image appears on

the computer screen in just a few minutes.

     Often, an artist is not even necessary. With practice,

investigators can place the features on the screen and modify the

image as the witness instructs. The system can be loaded into a

laptop computer to further speed up the process by taking it

directly to a crime scene. It can also be accessed via a modem

hookup or put online, with an artist in another city available to

prepare the composite while a witness views and suggests changes.

PUBLICIZING IMAGES

     Investigators should remember that even the most accurate

forensic images are of little value if potential witnesses never

see them. This is especially true of age-enhanced photographs.

     After sending the photographs to Federal, State, and local

law enforcement agencies, investigators should consider

additional ways to publicize the image. The more people who see

the image, the better.

     Generally, programs that spotlight criminals and missing

persons on national or local television and/or in newspapers

yield the best results. One investigator from Oakland,

California, reached out across the United States and Canada with

age-enhanced images of two missing brothers. After exhausting

every lead, the investigator turned to the television program

Unsolved Mysteries.

     On the evening of the broadcast, hundreds of calls poured in

from the Albuquerque, New Mexico, area. Authorities located the

children in a trailer on the outskirts of town, where they lived

with their mother and her new husband--a known drug dealer. The

boys were returned to their father, who had not seen them in

several years. Although the aged images of the boys were very

accurate, the relentless determination of the investigator and

the assistance of the public ultimately solved the case.

     Other methods can be used to publicize an image. Most States

have at least one agency dedicated to the location of missing

children that assists investigators in publicizing such cases.

Wanted and missing person posters often provide a worthwhile

medium. Many printing companies produce posters and flyers

concerning missing children at a reduced rate or at no charge.

Companies offering coupon advertisements featuring missing

children have also proven effective.

THE FUTURE

     New computer-assisted forensic imaging technology looms just

on the horizon. For example, the introduction of three-

dimensional digital skull imaging will give forensic artists the

ability to rotate facial images on screen, allowing for more

movement of facial expression and the addition of detailed facial

features to the image.

     New technology will also enhance superimposition

capabilities. For example, on-screen rotation of cranial images

will allow forensic artists to align antemortem photographs more

accurately.

     These and other improvements will enable forensic artists to

provide new levels of assistance to investigators. Further

computerization of the forensic imaging process promises to

provide law enforcement with enhanced facial identification

capabilities as the 21st century approaches.

CONCLUSION

     For decades, forensic imaging has benefited law enforcement.

Now, computer-assisted programs provide greatly improved

capabilities at a fraction of the time similar imaging once took.

When combined with the communicative power of modern mass media,

the impact of forensic imaging can produce impressive results,

even for cases once deemed hopeless.