ABSTRACT: We can say that as long as the crime is committed by a single participant, namely the perpetrator, directed against social values, for example: aggravated theft, destruction of objects that are not in his patrimony, fraud, blackmail, etc., and the victim does not have direct contact with the perpetrator, we cannot raise the issue of the appearance of the probative substance, namely human blood. From the point of view of specialists, on the spot, human blood can be found in various physical properties. For the beginning, the rule of time is applied, so that if the committed deed did not exceed a maximum of 24 hours, then the blood can be found in liquid state being easy to take. On the other hand, if the 24-hour deadline has been exceeded, forensic scientists can find traces of solid blood, of course, this will not prevent the specialist from taking the evidence found. KEYWORDS: evidences, blood, forensic, technology, laser method, biological, DNA, chemical