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another interesting problem. In a recent case, the Bureau had to determine whether pieces of "crack" cocaine came from a single cake. To make crack, cocaine HC1 is baked with sodium bicarbonate and solvent and formed into cakes, which are broken LABORATORY New Text when cooled. The pieces were seized by the investigaPROFILE tors and fit together like a puzzle. IR spectroscopy re~ The science of law vealed a match based on fibers that had fallen into the and order Analyzing one of thousands of samples. mixture before it cooled From standard breathalyzer tests to specimen is logged in at the crime DNA matches, state crime laboratories Polyethylene was also detected because scene until it or its analysis is brought must do it all—on a limited budget and polyethylene shreds were incorporated out in trial. When a blood or body fluid into the batch as plastic bags of cocaine under constant scrutiny by the police, stain is cut from a piece of clothing, were cut open the courts, the prosecution, the defense, the news media, and the public. Many of the bureau's remaining 8000 or one analyst witnesses another cutting it out and documents the procedure. The New Jersey State Police Forensic so cases involve "secondary transfer"— Generally the person who performs an Science Bureau, with four regional something from the perpetrator's environlaboratories, has responsibility for ana- ment sticks to him or her and is then trans- analysis follows the evidence all the lyzing all municipal, county, and state ferred to the victim or the crime scene. For way through and is responsible for drug evidence and breathalyzer samevidence from break-ins, the labs use FT-IR testifying in court. ples, as well as all physical evidence Another crucial area of responsibiland scanning electron microscopy with an from crimes ranging from homicides ity for the labs is bringing criminal inenergy-dispersive detector to analyze the to suspected arsons. With New Jerelements in paint scrapings from screwdriv- vestigators and theirfieldtechnicians sey's large urban population and the up to date on sampling and storage ers and other tools. In one assault case, expectation that almost techniques. Resources to perform analplastic shavings found on the victim were brings multiple specimens requiring analyzed by transmission FT-IR microspec- yses, including the amount of available sample, are limited; and not all analymultiple analyses the burden quickly trometry and GC pyrolysis. The evidence adds UD led police back to an individual who worked ses are relevant or necessary to solving the case. For instance, now that Last year, with fewer than 100 labo- in an auto body shop and WHS covered in blood and semen can be analyzed by shavings from his work. ratory staff, the bureau handled eviPCR rather than enzyme tests, differdence from more than 37,000 criminal Validation of analytical methods can ent preservatives are needed. cases, including nearly 29,000 drug become a significant issue for the bureau In fact, the labs in the last few years cases, says Thomas Brettell, the buin court. In the recent Megan Kanka case, have moved significantly into the area of reau's assistant chief forensic scientist. the child sexual assault/murder that reDNA analysis by PCR One bureau case For routine drug evidence, which dom- sulted in "Megan's Law,, the prosecution involved DNA extracted from the saliva inates the caseload, the bureau has a contested the bureau's hair andfiberevion the back of a postage stamp. A citicourt-mandated turnaround time of 15 dence linking Jesse Timmendiquas to zen had complained of receiving threatdays. Thus, the laboratories limit the Megan Kanka, citing the Daubert rullng ening letters. Using the PCR results in analysis to the minimum needed to that specifies that scientific analyses use further investigation, police showed that substantiate each charge usually pre- established points of comparison that are the citizen was the perpetrator. sumptive screening color, followed by acceptable in the profession. "Hair eviconfirmatory automated GC/MS. dence is more subjective than many other So far, the bureau labs perform DQUnusual drug cases do crop up. For comparisons and requires greater training alpha and polymarker locus matches, to interpret," Brettell explains. but Brettell says they have just received example, appropriate GC/MS stana National Institute of Justice grant to dards for anabolic steroids, popular The bureau labs use numerous methevaluate short tandem repeat analysis with bodybuilders, are hard to come ods in hair and fiber comparisons, includ(STR), a method he thinks is set to reby. Steroids typically come as injecting polarized light microscopy and FT-IR place the older methods in many state able mixtures of four or five different microspectrometry to identify and compare crime labs once they validate it. "Multihormones. Moreover, they are often dyes. Because the labs use only wellmanufactured overseas, and containers validated and published methods, the court plex DNA and STR methods are definitely on their way. CE isn't ready yet, are usually in foreign languages and allowed this critical evidence into trial. but I think you're going to see it in the frequently mislabeled. Brettell says the greatest protection for the bureau labs' work in court is maintain- future for DNA analysis." Tracing street drugs, usually dirty Deborah Noble ing the chain of custody from the time a mixtures, back to clandestine labs is
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Analytical Chemistry News & Features, September 1, 1997
