While enjoying your favorite flavor of television crime show, do you ever wonder if forensic crime work is really so instantaneous and glamorous? A few years back when a friend’s daughter aspired to be a forensic scientist, I found myself cautioning her saying “it’s not nearly as glamorous as TV portrays.”
Not wanting to spoil anyone’s aspirations, but toxicology, DNA, or crime scene trace evidence investigative testing results don’t arrive in minutes or hours – sometimes even before the autopsy is complete as shown in TV programs or the movies. And, analysts are generally dawning Tyvek or lab coats and various other protective gear so they don’t compromise the case.
The Reality in Forensics Labs
Ask a forensic scientist or their lab director about a day in the life of their lab and you’ll soon realize things like case load, turnaround time, inconclusive tests, test send outs, validation, chain of custody, and re-validation are part of their daily routine adding expense and time to their caseloads.
What is Forensic Toxicology Testing and What Makes it Tricky?
Toxicology is the study of the adverse effects of chemicals on living organisms. Forensic toxicology includes the detection and interpretation of drugs and poisons in medico-legal death investigations, human performance issues (e.g., driving under the influence, sports doping, workplace drug testing or probation compliance monitoring for drugs of abuse, or other related matters.)
Investigations generally have three main objectives:
Is the toxicant capable of contributing to death?
Is the toxicant capable of causing behavioral changes?
Is the substance present? If so; is the presence legitimate?
The ever-changing list of compounds makes the forensic scientists job anything but routine. For forensic toxicology testing associated with an autopsy, the medical examiner in combination with their local jurisdiction laboratory will decide the required toxicology studies to perform. In a recent discussion with a Florida medical examiner, I learned that they generally collect blood or other tissue samples from a variety of body regions because drug concentrations can vary by site.
Results comparatives are made to boost accuracy and confidence in true cause of death. Urine may be collected as well as other tissue from vital organs and stomach contents. Collection takes roughly 15-20 minutes and is placed in special containers to prevent contamination or sample breakdown. In the U.S., testing is completed by chemists or medical technologist (if outsourced to a testing lab) certified by either the American Board of Forensic Toxicology or American Board of Clinical Chemistry depending on the focus area for the analyst.
Outside the U.S., there are a variety of regional accreditation and certification entities. Most labs performing forensic testing are accredited to ensure uniform quality standards and mechanisms to ensure harmonization for a practice area; including international harmonization efforts.
Forensic Labs of the Future: Reducing Weeks to Days
In today’s labs, one medical examiner said, “the first thing we do is basic screening for drugs in urine and blood for drug classes such as opiates, amphetamines, marijuana, alcohol and barbiturates using a mixture of immunoassays, headspace samplers with gas chromatographs or other non-confirmational techniques. Each sequential step in the process requires time, chain of custody and validation to ensure the data will withstand the court of law.
If initial test results are positive, chromatography coupled mass spectrometry is used to identify the specific compound and quantify if needed. Quantification is useful to determine therapeutic, toxic or lethal dose levels. For inconclusive results, laboratories are increasingly deploying high-resolution mass spectrometry to design their lab of the future, now.
Using technology, such as the Thermo Scientific Q Exactive Focus Hybrid Quadrupole-Orbitrap mass spectrometer, may empower forensic scientists to accurately screen and quantify their standard compound list, as well as retrospectively re-investigate the same data set for unknown artifacts. Using new high resolution spectral libraries locally and updating them routinely via cloud-base applications, can reduce sample-to-answer time significantly. By deploying a single system for screening, quantitation and identification, future forensic toxicology testing may be completed in days or minutes versus weeks.
Forensic labs anticipate suppliers will continue to focus on portability, smaller product footprints, more automation, less paper and an overall ability to streamline the forensic workflows and minimize chain of custody pain points. The future of forensic labs may lead to TV programs being accurate in the amount of minutes or hours it takes to get toxicology results.