AAAS Responds to the NAS’s call for Research Backing Forensic Science

The American Association for the Advancement of Science (AAAS) announced that it will begin conducting an analysis of the scientific bases for ten forensic disciplines. Through funding from the Laura and John Arnold Foundation, AAAS plans to review the current scientific studies regarding the procedures and testimony of forensic experts. This analysis is a direct response to some members of the National Commission on Forensic Science’s comment that further study is needed to ensure that forensic science meets Daubert’s requirements for validity and reliability in expert testimony.

In 2009, the National Academy of Sciences released a report entitled Strengthening Forensic Science in the United States: A Path Forward which found that “forensic science disciplines suffer from an inadequate research base: Few forensic scientists have the opportunity to conduct research, few academics are positioned to undertake such research, and, importantly, the funding for forensic research is insufficient.” p. 187.

The AAAS analysis will be conduction quality and gap analysis of the following forensic fields in order to determine what existing research supports current practice as well as what additional research would strengthen the scientific foundation of each field:

1. Bloodstain Pattern Analysis
2. Digital Evidence
3. Fire Investigations
4. Firearms and Toolmarks/Ballistics
5. Footwear and Tire Tracks
6. Forensic Odontology- Bitemark Analysis
7. Latent Fingerprints
8. Trace Evidence- Fibers
9. Trace Evidence- Hair
10. Trace Evidence- Paint & Other coatings

This project poses a great opportunity to improve the quality of forensic science in the criminal justice system, ensuring greater confidence in the integrity of convictions. It will be important for attorneys to understand the findings of this analysis, as it may demonstrate whether admissibility of certain types of evidence should be re-examined. The AAAS analysis will be a solid step in addressing the flaws which the NAS noted in 2009, which the legal community has been trying to resolve since.

Additional information is available here.

False Positives in Drug Field Testing Kits

The director of a lab recognized by the International Association of Chiefs of Police for forensic science excellence has called field drug testing kits “totally useless” due to the possibility of false positives. In laboratory experiments, at least two brands of field testing kits have been shown to produce false positives in tests of Mucinex, chocolate, aspirin, chocolate, and oregano. However, law enforcement agencies continue to employ these kits.

Fox 13 Tampa investigated the validity of drug field testing kits in the wake of arrests of three people based on false positives from field tests. Eventually all three were cleared and all charges were dropped. However, for the months between arrest and confirmatory testing by the state crime lab, the individuals felt that they were “guilty until proven innocent.”

Dr. Omar Bagasra, a research scientist at Claflin University, has been looking into the validity of field drug testing kits. In controlled tests in his laboratory, Dr. Bagasra, Dr. Cherilyn Haggen-Paey, and forensic scientist Chris Addanki, have demonstrated that the chemicals used in the kits are prone to give false positives even with common household materials. According to their tests, Mucinex can produce false positives for heroin and morphine; chocolate can be interpreted as marijuana; and soap can test positive as GHB. Even exposure to air caused false positives in some kits, according to their tests. The scientists noted that they had trouble interpreting results in a laboratory environment and “you can imagine in the field it’s even more difficult.” However, the experts say the problems are not linked to just the individual kits tested or a specific manufacturer, as many the field test kits tend to contain the same chemicals.

Field drug testing kits were created to screen for illicit substances in the field followed by more complete testing in a laboratory setting. However, the tests stand in for more scientifically valid testing until analysis at state crime labs occurs. Drug testing at state crime labs is typically performed just prior to trial due to the high rate of plea bargaining in drug cases, and therefore false positives are often not discovered unless contested at trial. During this time, the false positives from field tests can cause innocent citizens to be detained in jail for weeks or even months.

“False Positive Equal False Justice,” a 2008 report created for the California Attorneys for Criminal Justice, noted that false positives resulting in criminal charges has been an ongoing problem. In 2003, a Pennsylvania college student was held for three weeks when flour was mistaken for cocaine. In 2007, musician Don Bolles was arrested for possession of GHB which was actually soap. Additionally the report lists approximately forty extracts—such as vanilla, peppermint, or ginkgo—which can test as false positives for marijuana.

Dr. Frederic Whitehurst, a Ph.D. chemist and former FBI lab supervisor, has expressed concern with the use of field drug testing kits. He stated that he has “no confidence at all in those test kits.” Due to the high chance of false positives, both Dr. Whitehurst and Dr. Bagasra have recommended that drug field testing kits not be used. They say law enforcement would receive more valid results by waiting for results from lab testing. The kits are single use and range from a $4 to $20 a use depending on what drug is being investigated.

For more general information on forensic drug analysis see http://www.ncids.com/forensic/drugs/drugs.shtml.

Click here to read an article about the 2011 arrest of a man in Buncombe County based on a false positive field test result of cheese and tortilla dough.