Indented writing, a very special type of evidence, is often overlooked. An Investigator may not even be aware of it.

Along with indented writing, this equipment also can be used to recover dusty footwear impressions.

.In a drug case or a kidnapping case, a note pad with no writing visible on it is the only piece of evidence. Is there no writing at all? Oblique lighting may reveal some indented writing on the top sheet of paper, but it can be really hard to see.

Attempts at photography may be less than successful. What can you do?

In another case, some papers and file folders from a burglarized business are submitted as evidence. The suspects entered through the roof and jumped down onto a desk. You can just barely see the faint impressions of footwear in dust on some of the papers and nothing at all on the others. It would be impossible to photograph these extremely low contrast images of dust on patterned or light colored papers.

What can you do?

A solution to both of these problems involves using an Electrostatic Vacuum Box , a Criminalist with the Swedish Police Force.

The Electrostatic Vacuum Box holds the paper down while film is placed on it and charged with electricity.

To Visualize Indented Writing on Documents If indented writing is being sought, the document is placed on the Electrostatic Vacuum Box and covered with Type IW plastic film. Switch the vacuum pump on. Electricity is passed over the surface with the use of a corona unit.

Special developing powder is applied with a fingerprint brush to the plastic film over the document. The powder collects in the indentations with the excess powder being brushed away.

The indented writing is now visible and can easily be photographed due to the high contrast between the black powder and the film. This film can be covered with an adhesive-backed film to preserve the powder-developed image.

The original document is not damaged or altered.

To Recover Footwear Impressions in Dust To recover the footwear impressions in dust from paper items, place the paper with the suspected dusty footwear impression on the Electrostatic Vacuum Box. Cover it with Type SP film and switch on the vacuum pump. Charge it with electricity using the corona unit. The dust, in the shape of the footwear image, will now be on the clear plastic film. Because of the vacuum, there is no air gap between the plastic film and the evidence paper. Since the particles of dust do not have to jump over this air gap between the film and the paper, the resulting image is sharper.

This procedure is suggested for use on papers from a crime scene, even if no footwear impressions can be detected with the unaided eye.

Excellent, high-contrast photographs of the footwear impressions can result with the use of a black background and directed lighting.

Specifications:

• Vacuum plate (35 x 39 cm)
• Vacuum pump
• 100-meter roll of Type IW film
• Transformer.
• 100-meter roll of Type SP film
• Developing brush
• 75 grams of developing powder
• Corona unit
• 25 sheets of adhesive film (25 x 35 cm)

Electostatic Vacuum Box, £1500.00

IW Film 0,4 x 100m, £68.25

Cascade Developer, 1-Kilo, £60.00

Black IW Powder-Fine, £41.00

ESDU Fixing Film, 25cm x 23cm, 100 per pack £74.95