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Can the timing of a sexual act be determined?

Dr Jagadeesh Narayanareddy, Vydehi Institute, medical examination, timing of sexual act, absence of injuries in rape, detection of sperm
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Can the timing of the sexual act be determined by a medical examination? For that the answer would be you picking up whether you are able to detect spermatozoa, whether you are able to detect injuries, whether you are able to detect sexually transmitted infection. But all this would have the limitations of post assault activities like washing, douching would remove the spermatozoa. Use of condom, and if it is not recovered, then spermatozoa would not be there. Use of spermicidal jelly, either pre sexual violence or post sexual violence. So that may also destroy the spermatozoa. The mucus secretion at the cervical region of the victim. So if there is excess of mucus secretion, the chances of you picking the spermatozoa would be longer.
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And the stage of menstrual cycle, if she is menstruating, then there is a possibility of these trace evidence to get drained with the menstrual fluid. Though sperm survive longer if the cervical mucus is thicker. And the presence of injuries, again, you need to go for picking up the time since injury, based on the changes. Sexually transmitted infections is another entity by which we can time. But for this we need to do two examinations . One examination as early as possible, whenever we have an opportunity to examine the victim. The next situation would be after the lapse of the incubation period. Here, a disclaimer, it’s not necessary that in every case you have a sexually transmitted infection.
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Unless until either the victim or the accused was harbouring that infection at the time of assault, there is no technical chance of you picking up a sexually transmitted infection. Suppose it’s a gonococcal infection. So the first examination did not detect first medical examination was done immediately after the sexual violence. But after four to five days, that is the incubation period of gonococcal infection, if a second examination is done and you find a gonococcal infection. So the accused had gonococcal infection, gonococcal urethritis and then there is a sexual violence.
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And the victim’s medical examination did not have gonococcal infection on the first day when we did, but after four to five days when I again do the examination, if I pick up gonococcal infection. So that proves that the sexual contact of this sexual violence, the possibility of this sexually transmitted infection, and that’s an indirect corroborative evidence to time the sexual violence.

Can medical examination determine the timing of a sexual offence? What role do detection of sperm, injuries or sexual transmitted infections play in this process? What factors contribute to their detection? Let us explore these questions with Dr Narayanareddy.

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