SEMI-ANNUAL SEMINAR (Spring 1957)
CALIFORNIA ASSOCIATION OF CRIMINALISTS
May 17-18, 1957
PLASTIC LIFTING TECHNIQUE
Jim Waston, L.A.P.D.
A report of experience with a lifting technique for dust shoeprints was described. The material used was black
neoprene 1/4" sheet, available in any size from West American Rubber Co., 1400 North Avenue, 19, Los Angeles,
Attention: Fred Warner -- $1.00 sq. ft. The dust can be flowed off with water and the neoprene reused. The black
background provides a contrasting background for lifted dust prints when the standard oblique lighting technique
GAS CHROMATOGRAPHY APPLIED TO ALCOHOL DETERMINATION
A discussion of gas chromatography was given with a representative of Beckman Instrument Company giving the
discussion on the technical details of the instrument.
3/100 ml sample size; Tween-20 column 6' long; helium carrier 120oC and 25 p.s.i.; solvents included
n-butyl ether, carbon tetrachloride, propyl acetate; Beckman GP-2 gas chromatography. These conditions will
separate and distinguish between ethanol and other alcohols, except isopropanol.
C.A.C. samples A-10, 5-10, C-10 extracted with equal portions of propyl acetate showed a straight-line
relationship of instrumental response vs. concentration of alcohol in the blood sample.
IDENTIFICATION OF MAN-MADE FIBERS
Anthony Longhetti, Minnesota State Crime Laboratory
A systematic scheme of identification for synthetic and regenerated fibers of U.S. manufacture in 1956 was
presented. The method involves a combination of melting point and optical properties. It was estimated that 25-30%
of manufactured fibers are man-made and will probably increase to 60% by 1960.
BLOOD ALCOHOL CONTROL TESTS
Results of the last C.A.C. test projects were discussed. It was decided by the group that an effort be made to
determine possible causes of error. Therefore the Executive-Secretary was directed to utilize the facilities of the
Laboratory of Criminalistics in San Jose to make a complete study, which would include questionnaires and samples,
if necessary. Dr. Kirk volunteered a standard sample of iodate, if it could be used in the study.
BLOOD GROUP TESTS WITH LECTINS
Ed Lewis, Hyland Laboratories
An Anti-A lectin was demonstrated which is made from a legumin seed occurring in India. Sources of the following
were described as being available:
A. Standard blood cells--stable for 5 weeks.
B. Control specimens for hospital-type blood chemistry.
C. Bacteriology media poured into disposable Petri dishes and sealed in polyethylene bags--stable 90 days.
SURFACE REPLICAS OF STAB WOUNDS
Gerald Ridge, M.D., Coroners Office, L.A.
A process was described wherein a pledget of cotton was inserted into the wound orifice. The skin was then rolled
with fingerprint ink and a roll-off was made onto a 3" x 5" card, suitably marked for orientation. Irregularities of
the knife edge were evident in a presented case study.
SOIL SAMPLE STUDIES
David Q. Burd
An illustrated discussion of 100 soil sample analyses was given by use of the density sedimentation technique.
MICROORGANISMS IN SOIL
A discussion was given of the possibilities of culturing non-pathogens in soil and comparative identification
Krylon sprayed on fired bullets preserved bullets from corrosion, and examination can be made through the plastic.
The plastic can be removed by solvent action.
OCCURRENCE OF METHANOL IN CORONER BLOOD SAMPLES
Elliot Hensel, Ventura Medical Laboratory
Methanol traces (5-8 mg/dL) in post mortem blood samples involving wine consumption attracted attention to the
presence of methanol in wines. Pectin hydrolysis produces methanol. Methanol excretion is 10 times slower than
ethanol. Little is known about the possible synergism between methanol and ethanol. 210 mg/dL methanol was found
in "Santa Fe" label muscatel.