California Association of Criminalists
Since 1954
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 is used.
GAS CHROMATOGRAPHY APPLIED TO ALCOHOL DETERMINATION
Jack Cadman
A discussion of gas chromatography was given with a representative of Beckman Instrument Company giving the discussion on the technical details of the instrument.
Technical data:
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
Jack Cadman
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
Duayne Dillon
A discussion was given of the possibilities of culturing non-pathogens in soil and comparative identification possibilities.
BULLET COATINGS
George Lacy
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.
