DNA evidence is one of the most effective tools available in modern law enforcement. For both violent and property crimes, DNA technology is often the critical factor in prosecuting the guilty and exonerating the innocent. Deployed strategically, DNA technology can improve prosecution rates, increase case clearance rates, act as a deterrent, and otherwise play a key role in systematic crime reduction. Conversely, haphazard deployment of DNA technology, namely focusing on the DNA laboratory alone without consideration of its role in the bigger picture, may lead to more work yet have little or no impact on the ultimate objective – reducing crime.
With recent advancements in both the underlying forensic science of DNA and its widespread application by law enforcement agencies throughout the United States over the last ten years, the amount of evidence requiring DNA testing has contributed to significant backlogs of forensic analysis throughout the country. As compared to even five years ago, today more material found at a crime scene can be probative which means more work to collect, process, analyze, and interpret results. This increased volume has a cascading effect both on the size of the reports and what is provided to prosecutors. Although many jurisdictions have taken proactive and strategic approaches and nationwide programs such as the President’s DNA Initiative have had an impact, significant CODIS and casework backlogs remain at all levels of government.
Data from numerous sources provide the necessary information to demonstrate a reduction in crime. As an example, according to the white paper “The Application of DNA Technology in England and Wales” by Christopher H. Asplen, J.D., the Forensic Science Services serving the England and Wales:
- Solves 0.8 other crimes for each crime solved with DNA
- Prevents 7.8 other crimes for each custodial sentence resulting from a DNA based conviction
- Increases the suspect identification rate for domestic burglary from 14 to 44 percent when DNA is available at the crime scene
- Maintains a 40 percent chance of obtaining a match between a crime scene profile and a “criminal justice” (arrestee or suspect) profile loaded into the database
An example in the United States comes from Denver which participated in a National Institute of Justice funded pilot study with four other cities. The study was to determine the effectiveness of DNA as a crime reduction tool by focusing on high volume crimes such as burglary, auto-theft, and theft from motor vehicle cases. According to a joint press release issued on June 10, 2007 by the Denver District Attorney and the Denver Police Department, Denver had the most hits on the CODIS (DNA database), cases filed with the DA’s office, and the number of cases prosecuted. Some of the specific results noted included:
- Identified over 40 prolific burglars since the project started November 1, 2005.
- A prolific burglar commits an average of 243 cases per year.
- Of burglary cases where DNA is recovered, the prosecution rate is five times higher than cases without DNA.
- The average sentence for burglars linked to DNA is over 12 years in prison (compared to six months without DNA evidence).
- In a recent case, after police arrested one man (who later admitted to over 1000 burglaries), the burglary rate in theWest Washington Park neighborhood dropped about 40%.
While it may seem from these two examples that crime is readily reduced with the use of DNA, obtaining the greatest benefit from DNA technology in reducing crime requires four critical elements: an integrated approach, critical feedback loops, measurement of progress and results, and effective processing of forensic DNA evidence.
AN INTEGRATED APPROACH
First, effective use of DNA requires an integrated approach. Efficiency and quality in the laboratory can only be achieved through changes to evidence collection and increased coordination with prosecuting attorneys.
For every individual case, the prosecutorial value of DNA evidence is only as strong as the weakest link in the chain from crime scene collection; handling and transport; forensic analysis and interpretation; and finally the resolution in the court of law. With the scientific basis of DNA identification long accepted, most defense bar challenges are limited to attempts to demonstrate (or suggest) human or procedural error.
As legislation, innovation, and funding have contributed to a substantial increase in the volume of DNA evidence over the past ten years, strategies and solutions that have and will continue to reduce crime must be guided by the fact that prosecutions are built one solid case at a time. In other words, the bottom line for any law enforcement officer, crime scene technician, evidence technician, or forensic analyst is to ensure that every time they collect, handle, transport, or analyze DNA evidence that they do so according to defensible procedures within accepted prosecutorial standards. However, all of these steps in the process are so interrelated that they not only have to be done correctly in and of themselves, but each step must also be in synch with the others as an integrated approach.