Chemistry in the justice system - Journal of Chemical Education (ACS

Chemistry in the justice system. James J. Hazdra. J. Chem. Educ. , 1980, 57 (1), p 24 ... Published online 1 January 1980. Published in print 1 Januar...
1 downloads 0 Views 3MB Size
James J. Hazdra Drector of Health Care Education Illinois Benedictine College Lisle, IL 60532

II

Chemistry in the Justice System

It is generally recognized that the input of chemistry into the justice system is mnstantly becoming more and more important. The total crime rate in our society is on the increase, and the need for fast crime detection can be accomplished only by greater application of scientific technology. Since the ways and means of criminals are becoming more sophisticated, the tools now available to the criminalist are alsn forever expanding, ranging from a simple magnifying glass to a scanning electron microscope. Definition of Forensic Chemistry Forensic science can he generally defined as the application of' scientific principles to the administration of justice. Forensic chemistry is a hranch of forensic science which involves the use of chemical principles and techniques in the examination of all types of materials that are items of evidence. Samples coikcted in criminal investigations that are used as evidence may he as varied as fihers, fabrics, glass, metals, building materials, soils, firearms, explosive residues, discharge residues, paints, rubber products, inflammable liquids and residues, fingerprints and palm prints, documents, inks, intoxicating compounds, drugs, cosmetics, hair, saliva, blond, seminal fluid, and urine. Ail these must he examined hy the criminalist using instrumentation ranging from the simple to the verv highlv sophisticated. The forensic chemist must always keepin minh that the results of his examination may assist t.he criminal investigation and will he used in a court. of law to prove the innocence or guilt of individuals. Historical Development of Forensic Laboratories On the morninn of Fehruarv 14. 1929, in Chicapo's near north side an infamous event took place which is now known as the St. Valentine's Dav Massacre. Five of the murdered 1ne11were found to he members ol'the "Hugs" Moran gang. A orohlem arose for the law enforcement olr'icials because it appeared as t.hough the Chicago police had heen involved in the massacre. The cortrnerat that time, Dr. Herman Rundesen. nrdered the collection 111.nearly 70 empty shells, hullets, and bullet fragments. Due to the unusual ci~mplexityof this case, a special jury of six men, all prominent in the Chicago Cnmmunity, was formed to study the case. Rret A. Massee, (.he vice-president ol'CoIgate-Palmolive Peet Co. was chair-

24 I Journal of Chemical Education

man of this jnry. The jury hronght in Calvin Goddard from New York City, who had gained a national reputation for his firearm work. Goddard quickly concluded that. all ofthe shells and bullets were fired from two .45 caliher Thompson submachine guns. The markings of the ctrllected bullets did not match any ofthe Thompson machine guns found in the Chicaeo nolice denartment. Almost eleven months later the ma-

..

in St. Joseph, Missouri. This set the stage in Chicaro for the establishment of the first crime laborat& in the l i k e d States. Massee continued his financial support and suggested that Chicago should have a crime laborati~rynot only for the purpose of identifying firearms, hut alsi~for the application of scientific methods to other hrands of criminal investigation. A lalrmatory corporation was formed and affiliated with Northwestern University in June 1929. Guddard became its first directw of the Scientific Crime Detection Laboratory which was the first of its kind in the nation. Northwestern's Chicago 1.aImrat11rythrough its sense of an educational mission. c&lurted information and training seminars. Attending these classes in I931 were agents from the agency now known as the Federal Bureau of Tnvestigation. This resulted in the estahlishment of an official Criminological Laboratory for the FRI in Washinelm. ~, . l1.C.. on November 24.1932, In 1943 the name was changed to the FBI Laboratory which today is one of the largest and hest eouinoed . .. laboratories of this kind in the Un~tedStates. Now there are over 250 crime laboratories in the United Slates. Enrh state and most major cities have one. On the FcvI~~.al Ievrl, in addition to 1 he FBI, Lhe Bureau of Alcohol, 'I'ul,arcu and Fiwarms. and the Thug Hnforcement Administratiun alw, have crime 1ai)uratories. However, the t,raining of manpnwer has heen a problem, especially for the newly organized laboratories. In the case of several newh develoned instrumental techniuues thev have outrun the (i,rensic scienlist's ability to utilize them as imuortant t w l s for rime detection. Much more developmental research is needed in applying all available analytical tools for crime detection. ~

~

Tools of the Criminalist However, crime lahoratories have come a long way since the oripinal laboratory in Chicago. Even those lahoratories quickly grew heyond firearm and fingerprint identifications. Summaries of a few major chemical instrumentation methods used in crime lahoratories follow. The classical wet chemical analyses (such as spot tests) described by Feigl' for identification of hoth inorganic and organic suhstances. Atomic Ahsorotion S ~ ~ c t r o p h o t o m ~ist rhecnming v extremely useful in'the anaiysis ojsoils, building materials, and alloy metals since it can tell how murh of each trace metal is present,. Recentlv. .. the advent of flameless praphite furnace techniques has increased the sensitivity of detection hy AAS and has virtually replaced the very expensive and t.ime consuming method of neutron activation analysis for t.rares of lead, barium. and antimony frnm firearms discharce residues. The rrlntiwlg nru \.AS trchniq~wih a w mad,. i t p,asildc to rrach pnrtr per bdlicm which mil\ ewn mcerd the limit5 nl'(l~:tecli(~n once afforded by neutron activation analysis. Chromatc~graphyhas long been used by forensic chemists. Particularlv in con. .oaoer . and thin laver chrnmatography junctitm a,ith intrnrrd El)r(lr~ph~llOlll~fr\. h.~\,eheen I I S P ~for drug and m~~taholite separ;iti,m :md iihtilicat~on.I t h:~>hwn greed grnerally that : ~ p p r ~ x ~ n n .ill ~ t ..Ul'', l y 01 thv work l < d d t h r lorcns~rchemi~tis in (It11g ~rlentiharion.I n ttrdrr t c ~ make this job easier, gas chromatography-mass spectroscopy (gcms) has heen employed for efficient separation and identification of drugs. Since most drugs and cosmetics cannot he volatilized. high performance liquid chromatography with ultraviolrt or Fourier infrared spectrophotometer as detectors are beginning t.o. he.utilized for manv fast seuarations and identifications. In addition to drugs, hoth quantitative and qualitative anal~

~~

useful information in crime detectinn. Ultrnoiolet nnd Fduormc~nreSpectroscopy have heen extremely useful in the detection of inks, invisible laundry marks. They routinely assist in preliminary examinations of seminal stains as well as altered or erased documents. Infmrrd Spectra have been extremely useful in distinguishing pigments and dyes that appear identical to the naked eye as well as identifying many robber, plastir. and other organic compounds.

elements have heen detected in a $20 hill which can he matched qualitatively and quantitatively to identify counterfeit money with paper and ink found on a suspect's premises. New techniques are constantly improving the use of EDXRF, and its usage will definitely increase in the forensic analytical laboratory. X-ray Diffraction powder pattern techniques have been used for 20 years or more in identifying and comparing unknown crystalline suhstances in the forensic lahoratory. The X-ray diffraction spectrometer records the manner in which X-rays are hent to identify mixtures of crystals found in huilding materials, explosive residues, different alloys, soils, etc. One of the hasics in forensic science is Locard's exchange principle that any contact between two objects, such as criminal and something at the scene of a crime cannot occur without transfer of material between them; however, the practical realization of that principle is often very elusive. I t is of interest to note that anv. oerson entering and exiting an . ;area lc:~\vas