Recovering Fingerprints from the Sticky Side of Submerged Duct Tape
Written by Ronald Becker, Peter Milosevic   

ABSTRACT: This research was conducted to determine whether usable latent fingerprint lifts could be recovered from the adhesive side of duct tape that had been submerged in fresh or salt water. The tape and prints were submerged for periods of time from 1 to 168 hours, half in fresh water and half in salt water. Prints were developed in two contexts: fingerprints laid on the adhesive side and taped to the adhesive side by folding the tape, and fingerprints laid on the non-adhesive side and taped to the adhesive side by folding the tape. Print values were designated on a scale from 0 to 5, traversing a scale from no value to AFIS quality. Samples that were adhesive side to adhesive side (A-A) produced 26 usable prints out of 80. Samples that were adhesive side to non-adhesive side (A-N) produced 78 usable prints out of 80, with 72 being of AFIS quality.

Water as a medium for criminal concealment

Earth is often referred to as the “Water Planet” because it is mostly covered in water. More and more human activity is taking place on America’s waterways. As the number of people using recreational waterways increases, so does the number of accidents, drownings, and violent crimes—including homicides that occur in these settings. This increase, coupled with criminals seeking a watery repository for weapons and other evidence of wrongdoing, has caused law enforcement agencies to become more involved in underwater recovery operations.

Many crime scenes are littered with duct tape and homicides are no exception. Bodies have often been disposed of in the water after being bound with duct tape (Dias & Dinge, 2003). Acts of terrorism could be committed using underwater improvised explosive devices (UWIED) with duct tape as a component (Truver, 2008). Drug dealers may package drugs and drop them into waterways for retrieval or while eluding the authorities. Regardless of the crime, tape can provide evidence with individualizing characteristics. One way it may do this is through the retention of fingerprints deposited on either side of the duct tape.

Fingerprints

Acquiring latent prints from adhesive sides of tape can be an arduous task beginning with unbinding the tape. A recent study found that manual separation yielded the best results. It was discovered that some adhesive separating agents had a limited detrimental effect on the fingerprints (Kapila & Hutches, 2012). The next step involved a method whereby deposited prints on the adhesive side of duct tape could be developed. In the early 1980s, the first successful development of fingerprints on the adhesive side of tapes was performed using dyes (Lee & Gaensslen, 2001). In 1994, Burns described the use of a sticky-side powder and a detergent that kept the powder in suspension, which yielded clear prints from the adhesive side of tape (Burns, 1994).

In a search of the literature, there have been a number of studies exploring the development of submerged fingerprints. However, there has been no published study documenting the ability and persistence of recovering fingerprints from the adhesive side of submerged duct tape.

Methods


Duct tape specimens were submerged in plastic, covered containers filled with freshwater (shown here) and saltwater.

Procedure—Approximately 10 liters of water were collected from the Pacific Ocean near Waikiki Beach, and another 10 liters at Palolo Stream freshwater creek running through Chaminade University campus. Each water sample was placed into separate 14-liter plastic, covered containers in the laboratory and allowed to acclimate to room temperature. The laboratory thermostat was held constant at 22.7°C (73°F) throughout the duration of the study.

A midgrade duct tape was cut into 6-inch strips and labeled with the time of submersion to which they would be subjected as follows: 1, 3, 6, 12, 24, 48, 72, and 168 hours. Each time interval had 11 samples for a total of 88 strips. Five strips were labeled for saltwater immersion and five labeled for freshwater submersion. The remaining strip for each time interval was utilized as an un-submerged control sample.

Two fingerprints were placed onto the adhesive side of each strip at opposite ends. The strips were folded into thirds towards the middle creating an adhesive side with a fingerprint bound to another adhesive side (A-A) and an adhesive side with a fingerprint bound to a non-adhesive side (A-N). Binder clips were attached to the strips as sinkers and samples were placed into the appropriate water container.

At the proper time of submersion, samples were removed from containers and water pH was compared to initial pre-submersion pH values. Adhesive remover was used to weaken the adhesive bond so that the tape could be separated. The strips were allowed to dry with the ends weighted to prevent the drying tape from curling.

Once the strips dried and the adhesive returned to its original consistency, fingerprints were developed from the adhesive sides of the samples using dark, contrasting adhesive-side powder in a solution of Kodak Photo-Flo 200. The Photo-Flo served as a detergent and kept the powder in solution. The liquid was then applied to the adhesive side of the strip being developed and left for ten seconds. After ten seconds, the adhesive-side powder and Photo-Flo were rinsed from the surface, revealing the previously laid fingerprints. Once the fingerprints were visualized, they were photographed and then preserved by covering with transparent fingerprint lifting tape. A qualified fingerprint examiner was consulted to establish a value for the prints obtained.

Results


Table 1—Quantity of Samples with Assigned Rating


Table 2—Quantity of Samples with Assigned Rating

Scoring Developed Prints—At the recommendation of the qualified latent fingerprint examiner, a subjective scale was established to determine the value of the developed prints. The scale was established as follows:

0 – No value, no first-level detail visible
1 – No value, first-level detail visible
2 – Elimination quality, first-level detail visible
3 – Elimination quality, first- and second-level detail visible
4 – Comparison quality, first- and second-level detail visible
5 – AFIS quality, first- and second-level detail visible

The fingerprint examiner examined each fingerprint and provided each print a number based on the scale referred to above. A summary of these assignments is provided in Table 1 (A-A) and Table 2 (A-N).

In analyzing the summarized data, there are fewer usable-quality fingerprints in the A-A samples, with 26 of 80 samples having some value (at least elimination quality), versus 78 of 80 A-N samples having at least elimination-quality value.

The results do suggest greater value in the A-A saltwater samples versus their freshwater counterparts. The saltwater A-A samples produced 18 usable fingerprints, while the freshwater A-A samples produced 8 usable fingerprints. The A-N samples produced usable fingerprints in roughly the same proportion in the freshwater and saltwater containers. Forty usable A-N fingerprints were produced from the freshwater container and 38 were produced in the saltwater container.

The data collected does not suggest a correlation between print quality and time of submersion. There were no noticeable trends over the course of one week of sampling, with some of the highest-rated prints coming from long periods of submersion.


Prints were developed on duct tape after specified periods of submersion. The prints shown here were developed after being submerged in saltwater for three days. The top two impressions were teh result of an adhesive-to-adhesive bond; the bottom print was an adhesive-to-nonadhesive bond.

Discussion

Latent fingerprints have been shown to be recoverable from the adhesive side of duct tape following submersion in water for up to seven days. This study demonstrates that fingerprints can be developed from the sticky side of duct tape after being submerged in freshwater or saltwater. The end result should be the creation of a protocol for handling duct tape that has been recovered in water that includes immersing the tape in water at the time of recovery. In essence, the tape should be packaged in water preferably while it is in the water. Immediate transportation to the laboratory would allow the described procedure to be employed.

About the Authors

This e-mail address is being protected from spam bots, you need JavaScript enabled to view it is a Full Professor at Chaminade University in Honolulu. He is the Chair of the Criminal Justice Programs and Past Director of the Texas State University Underwater Institute. He has taught underwater investigation since 1995 and each year teaches the Annual Underwater Forensic Investigation Workshop during May at Chaminade University in Honolulu, Hawaii. He is the author of Criminal Investigation 4th ed. and Underwater Forensic Investigation 2nd ed.

This e-mail address is being protected from spam bots, you need JavaScript enabled to view it has been employed as a criminalist for last two years in Honolulu, Hawaii and received his Master’s Degree in Forensic Science in 2011. He obtained the data presented here as a capstone research project under the mentorship of Dr. Ronald Becker in completion of his MSFS degree from Chaminade University of Honolulu.

Acknowledgements

The authors would like to express their appreciation of Hilary Moses, former Forensic Science Instructor at Chaminade, in providing an examination of the developed fingerprints and creating the scale upon which each was compared.

Thanks also go to Alicia Kvalheim, forensic science graduate student, who provided laboratory assistance in conducting this research.

References

Burns, D.S. "Sticky-side powder: The Japanese solution." Journal of Forensic Identification. 44(2) pp. 133-138 (1994)

Dias, G.A. and R. Dingeman. Honolulu homicide: Murder and mayhem in paradise. Honolulu: Bess Press (2003)

Kapila, T. and K. Hutches. "Methods for separating duct tape." Journal of Forensic Identification. 62(3) pp. 215-226 (2012)

Lee. H.C., R.E. Gaensslen, editors. Advances in Fingerprint Technology. 2nd Ed. Boca Raton: CRC Press (2001)


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