A stun gun can be used as an inexpensive method to recover dust prints in the field or in the lab. I recently checked several forensic supply catalogs and found that Electrostatic Dust Print Lifters cost approximately $785.00. A new smaller unit is available for approximately $625.00. That’s a bit pricey for smaller departments like ours. You can put together a kit that gives comparable results for under a hundred dollars.
The cost of our kit is listed as follows:
80,000 volt stun gun – Donated to us by local pawn shop
Fingerprint ink roller
Electrical leads (pair)
25 sheets lift film
Several manufacturers make sun-blocking films (window tint) that can be used instead of sheets of lift film for even greater savings. We obtained electrical leads from Radio Shack and soldered an alligator clip to one end. We use a 12″x16″ piece of steel cut from a discarded road sign as a ground plate. A section of cardboard wrapped with heavy-duty aluminum foil or a flat cookie sheet would also suffice. Sometimes it helps to anchor the lift film down to keep it from sliding around. You can tape it in position or a mouse pad cut in half so you have two pieces, one for both ends of the film, works well. The older, thicker style of computer mouse pad is heavier and has more grip.
The operation of the stun gun method is similar to the Electrostatic Dust Lifting Device. The lift film is placed over the dust print black side down. There are four probes on the top of the stun gun. The ones on the outside are the contact probes and the two in the middle are the test probes. Wire nuts can be placed on the test probes if you desire. The alligator clip on the wire lead is attached to one of the contact probes on the stun gun. The electrical charge is applied by holding the stun gun so the other contact probe is within a ¼ inch from the film. It works best to place it at one of the corners of the film. The stun gun is turned on and the other end of the electrical lead is guided around the perimeter of the film. Turn the stun gun off and wait 10 to 15 seconds before handling the film to allow any charge to dissipate. Then roll the finger print ink roller across the film to make better contact with the print. Turn the film over and shine a flashlight over the lift at an oblique angle to view the print.
Save the lift by taping it (black side up) in a cardboard box such as an unused pizza or keyboard box. We use discarded keyboard boxes obtained from a local business that regularly upgrades their computer equipment. Your photograph of the lift will be a reverse image so you need to flip the negative in the carrier prior to printing in the darkroom.
Newton Police Department
101 W. 4th Street S.
Newton, IA 50208