California Association of Criminalists
Since 1954
NOTES ON COLOR PHOTOGRAPHY
Ray H. Pinker, Scientific Crime Detection Laboratory, Los Angeles Police Department
The new color films Anscochrome and Ektachrome were discussed. It was pointed out that Ektachrome has the largest grain size of any of the color films. Anscochrome has a grain size approximately four times as small as Ektachrome and Kodachrome grain size is the smallest of all. The manufacturer recommends an ASA speed of 32 for each of these films; however, a rating of ASA 125 can be achieved by varying the time of immersion in the first developer. It was pointed out that the best results from the processing of Anscochrome result when 9.5 ag KI per gallon are added to the first solution and when the clearing solution is carefully adjusted to a pH of 8 with concentrated NaOH. Anscochrome results provide a cool tone and Ektachrome results provide a warm tone to the resulting transparencies. These tone variations are reduced as much as possible by a vigorous first wash of three minutes. The question of providing 3200°K illumination when making photomicrographs arose. It was brought out that a ribbon filament lamp operating at 18 amperes will produce 3200°K illumination for photomicrography.
REFERENCE SAMPLES FOR BLOOD ALCOHOL ASSAY
Lowell W. Bradford, Laboratory of Criminalistics, Office of the District Attorney, County of Santa Clara, Ca.
The preliminary blood alcohol assay results were presented and discussed. It was pointed out that problems were encountered in connection with the uniform reporting of results, units, and the matter of sufficient sample. It was planned to send out again standard samples with more detailed instructions as to the reporting procedure. All members who were present and who requested samples will receive these samples without further application. If any absent members or any non-members desire to receive the reference samples, the deadline for such a request will be January 10, 1956. Following the meeting a consideration of the non-member applications indicates that it may be necessary to charge a service fee to non-members for this service. This will be taken up with each applicant individually.
ALCOHOL DIFFUSION IN DEATH CASES
Henry Turkel, M.D., Coroner, San Francisco, Ca.
It was pointed out that Dr. Torkel's research shows significant differences in some cases between the blood alcohol content of femoral blood as against heart blood. Experimental work was conducted by inserting 6 ounces of 100-proof alcohol in the stomach of victims after death. It was then found, after various periods of time, that in two or three cases out of forty, a definite increase in the heart blood alcohol content occurred but did not occur in the femoral blood of the same cases. It is significant, therefore, that in death cases blood alcohol samples should be drawn from the femoral vein whenever possible. Possibilities of contamination by embalming liquids or pre-embalming liquids should be carefully avoided when these samples are taken in mortuaries or when involved in any way with a mortician or embalmer.
RELIABILITY OF THE ACID PHOSPHATASE TEST FOR SEMINAL STAINS
J. W. Brackett, Jr., Laboratory of Criminalistics, Office of the District Attorney, County of Santa Clara, Ca.
It was pointed out that there are many possible interferences with the acid phosphatase test which require controls and that the test is specific only when the proper controls are made. Interferences include commonly used vaginal douche materials. It was pointed out that l-tartrate specifically inhibits prostatic phosphatase. Vaginal fluid stains may give weak positive tests.
DERMAL NITRATE TESTS
Henry Turkel, M.D.
Dr. Turkel discussed his recently published paper in the Journal of Criminal Law, Criminology end Police Science, dealing with the paraffin glove as a means for detecting nitrate residues on the hands of persons suspected of firing lethal weapons. It was pointed out that Dr. Turkel's article did not consider the differences between a revolver and a pistol in regard to leaving residues and that his data included also rifles and shotguns which are not cylinder-type weapons. It was generally agreed by the group that the paraffin glove test was not a reliable means of testing for either the presence or absence of firearms residues and that it should not be used, as an investigative technique in this regard. However, it was pointed out that in some cases positive tests on areas of the paraffin gloves might lead to the microscopic finding of powder particles in these areas. It was pointed out further that microscopic examination of possible powder-burned skin areas might lead to evidence that there are firearms residues at those areas; however, it is not conclusive evidence that a person might have or might not have fired a lethal weapon. The residues could be present simply because of being in the proximal area of the firing.
DEMONSTRATIVE EXHIBITS, VISUAL EDUCATION DEVICES AND TECHNIQUES FOR COURT PRESENTATION
Lowell W. Bradford
This subject was introduced by way of a query, question and answer period during the course of which various sub-topics were considered. The question of stereoscopic photography was discussed and it was the general consensus that the individual viewing device is the best method for viewing and that the "Wollensack Viewer" at the present time is one of the best commercial instruments available for this purpose.
Highly efficient light source projectors were discussed and it was stated that the "Revere" 500 14 No. 888 projector with built-in pointer is one of the most efficient 35 mm. projectors on the market. For the purpose of projecting 3-1/4 x 4 lantern slides, it is believed that the "Spencer Delineascope" 750 14 instrument with forced air cooling is the best instrument available. Translucent screens for projection in brightly illuminated court rooms were discussed and it may be possible that more information on this subject will be forthcoming from the Eastman Kodak Company. The next issue of the "Newsletter" may have some information on this point. The use of color prints and color slides in court was discussed and it was generally believed that the color slide is a far better color presentation then the color print. It was determined also that it is common practice in various areas to use color slide projection instead of color prints in the demonstration of physical evidence. The use of Eastman Kodak translite film was discussed as a technique for the making of overlays in both the investigative phase of such comparisons as footprints and toolmarks and that it serves, also, as a valuable medium for demonstration in the court room especially for shoeprint comparisons. Explosion experiments were discussed and several cases in which these experiments have been made in the court room were reviewed. The employment of any dangerous experiments in the court room is not recommended.
SOIL ANALYSIS
Jack W. Cadman, Orange County Sheriff's Office, Santa Ana, Ca.
It was pointed out that techniques have been developed for the separation of soil components by density sedimentation techniques but that little has been done in the way of further identifying the fractions which are developed. The interpretation of known specimens was demonstrated and the possibilities of using the Munsell color classification were discussed and demonstrated. It was advocated that in density sedimentation tests the sample should be added to tubes before the liquids are added.
INTERNSHIP IN CRIMINALISTICS
Don M. Herding
Possible arrangements for the establishment of working internships in Criminalistics were presented so that students or graduate students might undertake a practical training program in the existing laboratories of the State. Pros and cons, and advantages and disadvantages of this type of a program were discussed with no definite conclusions.
THE FOLLOWING TECHNICAL NOTES WERE DEVELOPED AS A RESULT OF THE GROUP DISCUSSIONS:
1. Thioacetamide may be used as a substitute for hydrogen sulfide supply and constitutes a supply advantage over
hydrogen sulfide. The thioacetamide may be obtained from J.T. Baker Chemical Company at a price of approximately
$9.00 for l lb.
2. Specialized casting materials may be obtained from the L. D. Caulk Company, Milford, Delaware.
3. A photographic print developer which is variable for contrast may be used in lieu of variable contrast paper.
This formula is called "Beers Formula" and is as follows:
This is one of the most useful of all formulas, in that a wide range of contrast control is possible. The original formula calls for potassium carbonate; sodium carbonate can be used with complete success.
| SOLUTION A | SOLUTION B | ||
| Water | 750 cc. | Water | 750 cc. |
| Metol(Elon) | 6.0 g. | Hydroquinone | 8.0 g. |
| Na2SO3 - desiccated | 23.0 g. | Na2SO3 - desiccated | 23.0 g. |
| Na2CO3 - desiccated or monohydrated |
20.0 g. | Na2CO3 - desiccated or monohydrated |
27.0 g. |
| KBr 10% sol. | 11.0 cc. | KBr 10% sol. | 22.0 cc. |
| water to make 1000.0 cc. | water to make 1000.0 cc. | ||
These stock solutions are mixed in the following proportions to give a progressive range of contrasts. The lower-numbered solutions can be further diluted for very soft effects.
| SOLUTION No. /ounces |
CONTRAST LOW NORMAL HIGH |
||||||
| A | 8 | 7 | 6 | 5 | 4 | 3 | 2 |
| B | 0 | 1 | 2 | 3 | 4 | 5 | 14 |
| Water | 8 | 8 | 8 | 8 | 8 | 8 | 0 |
| Total ounces | 16 | 16 | 16 | 16 | 16 | 16 | 16 |
