This research aims to determine the time limit needed and the environmental conditions that provide the highest success rate in identifying dried blood samples on the fabric of stretch denim, ramie denim, black coated denim, and dry denim jeans using the elution absorption method. Also, to evaluate the effect of the fabric fabric, environmental condition, time, and interactions regarding the success rate of blood group identification. The study was conducted using 3 replications for each type of jeans fabric, which was carried out by exposing blood to a jeans fabric, leaving it in an indoor and outdoor environment for up to 336 hours (14 days), then continued by making a red blood cell suspension for comparison, and examining blood groups using the absorption-elution method. From the results obtained, it is known that the blood exposed in the jeans fabric that being placed indoor for up to 336 hours (14 days) can still be identified and has a success percentage rate of up to 100%. Meanwhile, the blood exposed on the jeans fabric that was placed outdoor could no longer be identified after 264 hours (11 days). Based on the result of this study, it can be concluded that the exposure time of 366 hours (14 days) for the indoor environment can still be identified properly, while the exposure time of 264 hours (11 days) for dry blood samples in the outdoor environment can no longer be identified. The indoor environment gives a better percentage of success than the outdoor environment in identifying blood types from dry blood samples. The best types of substrates that can store blood at an exposure time of up to 336 hours (14 days) are dry denim, black coated denim, and stretch denim.

Findings of blood at the crime scene (TKP) can provide important information in criminal cases such as homicide. Blood findings at crime scenes are usually blood spots or traces of blood that can be found on various substrates. This study aims to determine the type of wall substrate and environmental conditions that have the ability to preserve blood better, prove by success rate in identifying blood type in ABO system until 336 hour of exposure. In this study, blood samples were exposed to three variations of wall substrates, namely plastered walls, plastered and painted walls, plastered and oil-painted walls; and in two different environmental conditions (indoor and outdoor). The method used to identify blood type in this study was absorption elution. First, blood samples from substrate was transferred to a gauze by NaCl 0,98%. Then a confirmation test was carried out to ensure that the gauze sample contains a blood sample. Positive results of the confirmation test were indicated by a change in the color of the sample to bluish green when it is dripped with H2O2 and Leuco Malachite Green (LMG). The positive sample was then dripped with antiserum to determine the blood type. The success of identification of blood groups was indicated by the agglutination in the samples that were dripped with antisera A, because the blood samples used in this study are group A. The results showed that the success rate of blood group identification on the three types of substrates in the indoor environment for 336 hours was 100%. Meanwhile, in the outdoor environment, only blood samples exposed to plastered wall substrate and wall paint for 264 hours could be identified for their blood type. It can be concluded that the three types of wall substrates have the same ability to preserve blood samples for up to 336 hours of exposure, but the environmental conditions that give the best percentage of successful blood group identification were in indoor conditions. For further research is recommended to focus on external environmental factors that have the most influence on the success of blood group identification in dried blood samples.

Most of the criminal cases leave traces at the TKP (Tempat Kejadian Perkara) which can be used as evidence to reveal the culprit and the chronology of events that have occurred. Blood is the most important biological evidence in TKP. Through experimental research with a completely randomized design (CRD), this study aims to determine the success rate of blood groups identification in different types of Sengon (Paraserianthes falcataria L. Nielsen) as wood substrate in open and closed environmental conditions up to a certain time period. The four variations of Sengon wood substrate used were natural wood, processed wood, painted wood, and varnished wood. After 336 hours exposure on wood substrate, blood sample on the substrate was confirmed to identify the ABO system blood group using the absorption-elusion method. The results showed that the success rate identification the blood groups in ABO system on all types of Sengon wood substrate in closed environmental conditions reached a 100% for observation periods until 336 hours. Despite, the success rate of blood identification from all types wood substrate in open environmental condition were 0% for observation periods until 336 hours. Those data was then tested for normality with SPSS. The results showed that the data are not normally distributed (sig >0,00) for all type of treatmment. So that non-parametric statistical tests were carried out. The results of the Kruskall Wallis test showed that there was no significant difference between the treatment of Sengon wood substrate types and also in the length of time of observation (sig value 1,000). While the significance value on the environmental condition variable is 0.000, so it was concluded that there was a significant success rate's differences of blood group identification in samples that exposed to an open environment compared to a closed environment. This is reinforced by the results of the Kendall's correlation test and Spearman's test which show a strong correlation between the percentage of successful identification of blood groups and environmental conditions (correlation of 1,000). While the correlation value between the percentage of successful identification of blood group with the type of substrate and the length of time of exposure are 0.000 and 0.000, which is indicates a very weak correlation between the percentage of success of blood group with the type of substrate and the length of time of exposure. It can be concluded that the four types of wood substrates in closed environmental conditions had the same good ability to preserve blood within an exposure time of up to 336 hours. But, sample exposure in a closed environment provides the best percentage of success rate identification the blood groups in ABO system rather than the open environment was.