Detectability of semen remained in a condom under various conditions

Some research has identified the prevalence and motivation of using condoms by assailants during sexual assault cases proving the necessity of analyzing condom trace evidence. The majority of the papers published have discussed forensic analysis of lubricants from condoms retrieved at sexual assault scenes but those discussing the identification of semen from condoms are rare. Therefore, the present study aims to provide insight into the detectability of the semen that remained in a condom, to examine the effect of exposure time, environmental conditions, and condom type, and ultimately to determine the capability of the AP test and Microscopic examination for identification of this sample type. In the study, samples were collected from three male donors after being instructed on the proper way of collecting the semen sample. The received samples from the donors were checked first by microscopic examination to observe the sperm to confirm that the sample being handled was semen. After confirmation, samples were transferred to 4 prepared condoms (brands: dkt xxx and Manforce) and kept in conditions i.e. two condoms in a refrigerator maintained from 2 to 10°C and other ones at ambient temperature (weather status: summer season of average 39°C). The samples were analyzed into two batches, the first analysis batch was conducted after the samples were exposed to the conditions within 11–60 days. After analysis from the first batch, the samples were continuously kept in the same condition for the consecutive second batch conducted when the samples reached 40–90 days. This study has determined that semen remaining in a condom can be detected and each test studied is appropriate according to the exposure stage, i.e., time and conditions of exposure. It has been found that nonmotile spermatozoa can be observed when semen remains in the condom for a few days. However, if the sample reaches approximately 25 days at room temperature above 25°C or 54 days below 10°C, the semen may dry out limiting the effectiveness of microscopic examination. Despite this, even semen that remained in a condom for up to 90 days can be identified by Acid Phosphatase. Results on condom type used reveal that condom constituents can crossreact with semen but none of them can limit the semen identification with Acid Phosphatase.