الفهرس Only 14 pages are availabe for public view
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Abstract
The purpose of any medicolegal study of material evidence is to obtain as much information as possible. Blood is the most common well known and perhaps the most important evidence in world of criminal justice today. Bloodstains at the scene of an accident or a crime are a source of material for a wide range of investigative studies. Being able to estimate the age of bloodstains is an important task in forensic science. The determination of bloodstain age is desirable when the bloodstain has to be related to the time at which a particular crime was committed.
Concerning the lack of literature reporting the age of bloodstain, in farm animals, the present study has been designed to reveal the relationship between the change of some blood constituents and the age of bloodstain.
The present study was carried out on 2160 bloodstains samples obtained from cattle, chicken and consenting human volunteers (720 each). The bloodstains samples of each species were divided into equal four groups (180 each) concerning the four media (cotton fabric, iron, wood and soil). The samples of each media (180) were divided into three groups for the estimation of absorbance, enzymes (LDH, AST and ALT) and total proteins at 24, 48, 72 hours, 1, 2, 3 weeks, 1, 2, 3, 4, 5 and 6 months post-staining.
The results of absorbance values of bloodstains showed a significant decrease in relation to ageing. The results of the present work showed slight differences in the mean values among cattle, chicken and human being. However, among the four target surfaces, the highest values of the bloodstains absorbance were noticed in the samples stored on the iron while, the bloodstains stored on soil, cotton fabric and wood showed a comparable less values
The activities of LDH were disappeared in 6 months of all the stored bloodstains except the bloodstains of cattle and human stored on soil, their activity disappeared at 4 months. Statistical evaluation of regression of LDH activities on the age of the bloodstains revealed significant regression relationship.
The study revealed that the activity of AST was disappeared in all the stored bloodstains at 5 months except the bloodstains of chicken and human stored on soil the activity was disappeared at 4 months.
The activity of ALT was disappeared in bloodstains of chicken stored on cotton fabric and wood at 3 weeks, in case of the bloodsta- -ins of cattle, chicken and human stored on soil the activity disappeared at 1 month. The ALT activity of the bloodstain of chicken stored on iron was disappeared at 2 months while the activity of all the rest of bloodstains samples disappeared at 3 months. Statistical evaluation of regression of ALT activities on the age of the bloodstains revealed significant relationship.
Our results revealed that the earliest significant decrease of total proteins was showed in human samples while; the latest significant decrease was showed in cattle samples. The early significant decrease in total protein was recorded in samples stored on the iron. Statistical evaluation of regression of the concentration of total proteins on the age of the bloodstains revealed significant regression relationship.
The final results of the present study indicated that the estimated parameters (absorbance, enzymes activities and total protein) showed no significant variation between the three investigated species (cattle, chicken and human being). A significant variance was recorded regarding the different studied media. The recoded results were statistically expressed in equations, which is easily to be used for estimation of bloodstains age.