Forensic tools solve new, cold cases

Since before the advent of television shows such as the CSI dramas, DNA had been heralded as an unparalleled crime-solving tool. Unfortunately, as scientists, law enforcement and legal practitioners know, while the acquisition of a sample has become quite simple, the profile development and analysis remains complicated, time-consuming and expensive—certainly longer than an hour with commercials. Moreover, once a sample has been submitted for comparison to a state or national DNA database, it can be months or even years before a comparison is made and a perpetrator identified.

The backlogs encountered with national and state databases often hinder investigations and delay justice. In order to expedite the crime-solving efficacy of DNA, local police in more than four states--including Pennsylvania, California, Florida and Connecticut--are developing their own DNA databases. Law enforcement in those areas note that the local DNA databases have allowed them to avoid backlogs of national and state databases and solve some crimes much faster. For instance, one department cited the state lab taking nearly two years to process crime scene DNA, while a local private lab was able to complete the work in a month.

Accounting for some of the national and state backlogs are oversight and regulations. Some of those regulations govern where DNA samples come from and how long the profiles need to be maintained. The law hasn’t quite caught up with local DNA databases. Although each sample in the local DNA databases is purported to be a voluntary one with no threats or coercion applied, many include samples taken for investigative purposes. These might consist of people never arrested or convicted of a crime and juveniles who consent prior to any parental contact. In the case of juveniles, some local police departments obtain the juvenile’s consent, secure the DNA swab, then inform the juvenile’s parent or guardian that a swab was collected. In fact, in February 2017, the American Civil Liberties Union (ACLU) filed a lawsuit against San Diego regarding the collection of DNA samples from juveniles.

While many recognize DNA as the crime-solving tool of the day, fingerprinting has been around for some 100 years, and since 1999, the FBI has been responsible for maintaining a national finger and palm print database with submissions from federal, state and local law enforcement agencies. The FBI has upgraded the system it uses to store and match prints; and, since mid-2013 the FBI has been notifying law enforcement agencies to resubmit crime scene prints that did not turn up matches.

New developments with examination of finger and palm prints are helping to solve cold cases around the country. Called Next Generation Identification (NGI), the upgraded system stores and more sensitively matches the swirls and ridges on latent or crime scene prints with prints collected during an arrest. The system’s database also includes prints collected as part of employment and visa applications, as well as 45 million facial photos. With the upgraded system, the FBI claims matches are three times more likely. In fact, two unsolved rape cases were charged in Ohio, and a cold case project from the Oklahoma State Bureau of Investigation was able to identify some 150 crime scene prints. The number of charges and/or prosecutions was not reported.

While the new system may be able to solve some violent cold crimes, cash-strapped law enforcement agencies are faced with weighing the cost of re-opening and re-submitting the unsolved cases against unsure prosecutions in the face of statutes of limitations.

Finally, Bones fans will be happy to know that forensic anthropology is alive and well. While skeletal remains provide clues to a person’s gender, ancestry and other information, age at the time of death has been somewhat elusive. This information is complicated by the wear and tear that individuals place on their bodies.

One particular bone, the pubic symphysis, has allowed anthropologists to subjectively estimate age based on their observations and experience. Recently, Stanford anthropologist Bridget Algee-Hewitt presented on a more precise analysis based on 3-D imaging. Her method examines three different aspects of the bone and incorporates the measurement of some 40,000 points per square inch. The results have been providing quantitative estimations that can be reproduced and are taking subjectivity out of the equation.

While more research and larger samples are necessary to increase statistical accuracy, experts are excited by this development, which could become an important tool in forensics to determining age at death. 