T h e Laboratory's Role in Criminology
RICHARD
L.
DEMMEELE,
Associate Editor
F r o m " a n i a i x , a m i c r o s c o p e , a n d a d i r t y s i n k " tlie l a b o r a t o r y of N e w Y o r k P o l i c e D e p a r t m e n t l i a s g r o w n t o a staff of 23 ^vith 14 r o o m s . · . T l i e scientific m e t h o d s of this laboratory h a v e set tlie p a c e for c r i m e d e t e c t i o n l a b o r a t o r i e s i n the United. S t a t e s
R,
LALPH Waldo Emerson once wrote . . . "Commit a crime, and the earth is made of glass. Commit a crime, and it seems as if a coat of snow fell on the ground, such as reveals in the woods the track of every partridge and fox and squirrel and mole." Unfortunately, a telltale coat of snow does not always precede the perpetration of a crime. To assist them in appre hending the criminal, modern police organizations have had to create a more reliable if not so poetic device, the scien tific crime laboratory. The effectiveness of European laboratories of this type has been legend for years. In America, crime and consequently criminology matured at a somewhat later date than in Europe. It is in com paratively recent times that law enforce ment agencies in this country have interested themselves in the potentialities of the scientific laboratory. Once its utility was seen, however, its application was vigorously pursued with the result that American federal and municipal police laboratories now occupy leading positions on the advancing frontier of criminology. An outstanding example of the latter type of organization is to be found in the laboratory of the New York Police De partment which was started in 1934 at the suggestion of the late Chief Inspector John J. O'Connell. From a humble beginning, described as con sisting of " a man, a microscope, and a dirty sink," it has grown into an efficient modern laboratory with a staff of 23 and 14 rooms of diversified scientific equip ment. All of its personnel, of which only three are civilians, have received technical training at a college level, 10 of them holding masters' degrees and one a Ph.D.
Natural History. Exchange of information and techniques is also maintained with the laboratories of other law-enforcing agencies throughout the country including the famous technical division of the Federal Bureau of Investigation. The New York Police Laboratory oc cupies an important position in the organizational structure of the depart ment. Situated at Police Headquarters, it operates on a level with the homicide, narcotic, safe and loft, and other central office squads. Its commanding officer, Acting Captaki E. F. Fagan, is also in charge of the activities of the Ballistics and Bomb Squads with whose work the laboratory is often concerned. Captain Fagan is directly responsible to the chief of detectives. The basic function of a police laboratory is that of augmenting regular police methods of linking the criminal to the crime by the scientific gathering, exami nation, and evaluation of possible evi dence. This usually means finding traces of the suspect upon the victim or the scene of the crime, or traces of the scene or the victim upon the suspect. Comparison techniques predominate in the 100,000 determinations the New York Police Laborator}' makes annually in the investi gation of over 3,000 cases. Demonstrable identification of the so-called clue with its suspected source strengthens the case
of the prosecuting attorney and as such is turned over to his use. Dissimilarity between the two wall vindicate the inno cent party and suggest other channels of investigation. I t is a distinct tribute to the scientific objectivity of this laboratory that its integrity has never been questioned in court. Although technical experts -for the defense in the past have challenged some of the scientific procedures used by the laboratory, it has never been accused of adopting a prejudiced attitude in its investigations. Because of this, legal proceedings have seen an ever increasing admission of laboratory evidence and testi mony in recent years. And on IVheel s If mystery fiction writers had their w-ay, murder would be the only crime the New York Police Laboratory wrould be concerned with. Howrever, it interests itself in cases of burglary, auto-theft, narcotics, assault, rape, arson, theft, hit and run, and the "w-hite collar" crimes of forgery, embezzlement, fraud, and ex tortion. In many of these crimes, the trail of the criminal grows "cold" very quickly, and it is necessary that the lab man visit the scene promptly. For many years this was accomplished b y equipping the specialist from the labora tory with a portable kit of apparatus t h a t was appropriate to the particular crime and rushing him to the scene. Like the proverbial plumber, however, he would usually find upon arriving that some other tool which had been left behind
James J. Manning, chief phy sicist of the New York Police Laboratory. is shown using a spectrograph in the laboratory
Consults Other Laboratories Additional technical strength is given the group by an impressive list of con sultants and cooperating laboratories who render specialized services when needed. These include other New York City municipal laboratories such as those of the Department of Purchases, the Central Testing Laboratories, the Board of Health, and the Medical Examiner's office. The nearby facilities of Columbia, Fordham, and New York Universities are also on call as are those of the Bell Telephone Laboratories, the American Cyanamid Co., and the Museum of 456
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of laundries who u s e invisible fluorescent inks t o avoid disfiguring the garments. Similarly ultraviolet radiation is useful in revealing hidden writing on documents and in photographing fingerprints on multicolored surfaces. I n the latter case, ordinary fingerprint powders would not set off the print sufficiently from its back ground to permit a good picture to be taken. When fluorescent powders are used, however, and the photograph m a d e under ultraviolet light, a well defined image is obtained. Surround
View of one gas analysis
of the chemical rooms showing apparatus in the background
would do the job m u c h better. T h e an swer was to bring t h e laboratory with him. T h e New Y o r k Police D e p a r t m e n t Laboratory, realizing this, constructed in 1941 a crime detection laboratory truck outfitted with several thousand dollars worth of diversified scientific equipment. Included in it are t w o x-ray units, a motor generator set, a complete photographic dark room, fingerprint apparatus, a small chemical laboratory, microscopic and camera e q u i p m e n t , ultraviolet lamps, an electromagnetic retrieving a r m for the recovery of weapons, a time bomb detector, fluoroscopic equipment, plaster and moulage casting apparatus, a n d a wide a r r a y of s m a l l laboratory a n d ma chine tools. T h e mobile laboratoiy makes an a v e r a g e of 74 t r i p s a month. T h e above list only partially emphasizes the e x t r e m e flexibility needed in a modern police laboratory both with regard to men a n d a p p a r a t u s . Conventional tech niques and e q u i p m e n t can and do suffice for m o s t routine investigations, b u t the possibility always remains t h a t a par ticularly difficult obstacle will b e en countered on a case. This means t h a t a procedure m u s t be developed on t h e spot —a procedure t h a t will hold scientific water against t h e b o m b a r d m e n t of tech nical experts for t h e defense. Laundry IMarks Filed T h e e q u i p m e n t of the h e a d q u a r t e r s laboratory is m o r e diversified t h a n t h e mobile unit. A m o n g these facilities are the a u t o lens file and the d r y cleaner's and l a u n d r y m a r k files which h a v e been responsible for m a n y of the miraculously quick arrests. T h e a u t o lens file, useful in hit a n d run cases, consists of duplicate lenses of every t y p e of a u t o headlight m a d e prior to t h e almost universal adoption of t h e sealed beam h e a d l a m p in 1940. T h e V O L U M E
2 6,
NO.
the left
file is indexed according t o lens diameter a n d notch arrangement, t h e latter being described in angular degrees. Prism arrangement, flange angle and shape, and convexity are other i m p o r t a n t proper ties noted. Checking of the physical properties of t h e bits of h e a d l a m p glass found on t h e victim of a t "the scene of a h i t a n d run incident with this file's d a t a is often t h e means of t y p i n g the guilty car. Clinching scientific evidence is fre quently found in s p e c t r o g r a p h ^ compari sons of p a i n t particles o n the victim's clothing with t h e paint c o a t of the sus pected auto and in the checking of the bat ter's tire t r e a d s with the tire tracks left a t t h e scene. Handwriting
Samples
Ύοο
T h e laundry and dry cleaner's. mark files are maintained by t h e almost 100% cooperation of New York trade associa tions of those fields. Operatives from the police laboratory keep t h e s e files up to date by visiting laundries and cleaning establishments and noting any changes in marking methods. A file is maintained of handwriting samples of the employees who are charged with the task of number ing t h e g a r m e n t s . An example of the value of this file occurred recently in N e w York when b y i t s use t h e attacker of a young matron was apprehended within 24 hours after the crime. T o gain a d m i t t a n c e to her a p a r t m e n t he assumed t h e guise of a window cleaner a n d had t o r n an old shirt into three supposed cleaning rags. Fright ened awa3'p by the sound of neighbors coming in answer to her screams, he left these rags behind and on them his signature in t h e form of a laundry mark. Instrumentation Ultraviolet light of various spectral ranges is necessary to reveal t h e marks
7 » » FEBRUARY
1 6,
1948
Rullet
Hole
Often in shooting cases, the establish ment of evidence d e p e n d s upon determin ing t h e distance between the gun and victim a t the t i m e of firing. Infrared photography i s employed to locate the circle of unburncd powder particles t h a t surround the b u l l e t hole on t h e victim's clothing, a circle whose radius is propor tional to the distance a t which the given gun muzzle was held. Semipeiietrating "soft" x-rays are used to locate on the victim's clothing the lead particles that are shaved from the bullet by t h e bore of the gun a n d which follow it to i t s target. T h e s e b i t s of lead arrange themselves around the bullet hole a t a distance thai, like the case of t h e powder residues, is indicative of the space t h a t separated the m u r d e r gun from its victim. Both of these relationships hold only when this range is a few feet. It h a s been said t h a t n o modern labora toiy is complete w i t h o u t a spectrograph. At t h e police laboratory it is often the only unquestioned link between the criminal and his crime. T h e following are from case histories in the files of the New York Police D e p a r t m e n t ' s Labora tory : A knife blade broken off in t h e victim's body fit perfect ly, u n d e r stereoscopic camera inspection, i n t o the fractured part of the hilt t h a t was found on the suspect. It remained for t h e spectro graph, however, to show conclusively that t h e steel composition of t h e separated parts was the s a m e . T h e spectrogram of a watch crystal found a t the scene of a burglary coincided • completely with t h a t of a minute fragment of glass that had remained in the watch on t h e suspect's a r m . T h e seemingly airtight alibi of a sus pected murderer was shattered by a spectrogram of t h e dried m u d on his shoes. I t was identical with t h a t of t h e mud underneath t h e bushes from which he h a d ambushed his victim. M u d of the exact same composition was not found at an3 r other p o i n t in the vicinitj'. N o account of t h e i n s t r u m e n t division would be complete without, mention of those two workhorses, the microscope and t h e camera. T h e y feature or supple ment other a p p a r a t u s a n d techniques in almost every determination t h a t is made. The microscope notices a n d compares the invisible traces of guilt t h e criminal leaves behind a n d by photomicrography 457
Interior vieic of tl e crime detection laboratory truck taken, from the rear of the truck looking forward. The door to the photographic dark room can be seen in the background. Out lined in the doorway is a developing tank, in left foreground is a motor generator set. In right foreground is a reel cable that is used to carry current away from truck for uses such as x-raying suspected bomb packages the camera freezes these revelations into exhibits for juries to examine. The "wet method" chemical analysis problems of the New York Police Labora tory are as extensive as those of its instru ment work. The philosophy that pre vails is one of positively identifying the composition of a critical substance or substances found on the suspect, scene, or victim. This practice may n o t always provide the dramatic link between the criminal and his deed, b u t it does lay the groundwork of routine facts necessary to make a case stand up in court. Four Tests for
Blood
An example can be seen in the case of blood stains where superficial examina tion is far from sufficient cause to claim that the particular stain is h u m a n blood. Four deductive and detailed determina tions m u s t be run before such an assertion can be made:
photomicrography to demonstrate that actual spermatozoa are i n the specimen before these organisms die or become de stroyed. Unless the picture of at least one complete spermatozoon can be shown, such evidence is not admissible. In certain instances, it has been possible to type the seminal fluid a n d thereby give more strength to the case against a sus pect. Most chemists probably believe t h a t a stinkbomb containing m e r c a p t a n s o r oil of valerian would be self identifying. For purposes of jurisprudence, however, it is necessary for the police laboratory to show b y chemical analysis that the b o m b actually did contain these odorif erous substances. Such olfactory weapons are often used in rabor troubles to drive customers from a strikebound t h e a t r e or store. T h e trace impurities in their contents a r e often t h e m e a n s of linking t h e m to t h e spot at which they were made and the stink-bombardier himself. Examine
Poisoned
Food
I n cases of D.O.A. (dead on arrival) samples of the atmosphere in the room where the body is found a r e often collected. T h e cause of death m a y b e the failure of refrigeration equipment o r a leaky stove. A survey of the premises is m a d e with a C O detector to determine t h e extent of the spread of the gas. A t the same time a more detailed gas analysis is made from the collected samples in the Shephard and Burrell gas analysis a p p a r a t u s at the headquarters laboratory. Other analytical functions of the New York Police Laboratory are t h e exami nation of poisoned liquor, food, and suspected narcoticsChemical techniques a r e also used in the development of l a t e n t fingerprints. T h e body fluid that makes up t h e finger p r i n t consists chiefly of a n aqueous solu tion of sodium chloride with a b o u t a 1 t o 2 % content of f a t t y acids. When the print is old much of the water has One of the instrument
rooms
evaporated and it is difficult to obtain a good photograph. I n such cases, the surface holding the print is exposed to iodine fumes which revivify t h e image by adhering to the outline of t h e fatty acid residues. • For the development of fingerprints on materials difficult to work with by using powders, t h e New York Police Labora tory employs a technique developed by themselves. T h e fabric is immersed in a solution of silver nitrate which converts the sodium chloride in the p r i n t to silver chloride. T h e specimen is t h e n exposed to a light source which darkens the silver chloride portions photoehemieally. The swirls of t h e print will contrast sufficiently with the background to p e r m i t a good photograph. Unfortunately, space does n o t permit a longer dissertation on the many other operations of this laboratory. But. here is a true laboratory of applied science, one in which there is no hesitancy to use any field of specialized knowledge necessary t o do the job. When a bullet is fired the cartridge case is forced1 back against the breech leaving characteristic markings on the case. Photo beloiv shows markings made on two cartridge cases taken from the same gun. Note area to the right of the firing pin indentation
of the New
York
Police
Laboratory
Benzidine Test: a preliminary deter mination to show that the material is organic matter. Haemin Crystal T e s t : a microscopic study known as the Teichmann Test is run to show t h a t material is blood. Often followed by absorption spectra studies. Precipitin Test: anti-human sera is used to show that the now proved blood sample is not from an animal source. Grouping: can be run when the sample is fresh. Will show h u m a n blood group to which it belongs. In rape and other sex crimes a similar procedure must be followed. Biological samples taken from the victim's person are analyzed for protein m a t t e r by the Florence Test for spermatic fluid. The case is substantiated by the rapid use of 458
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