Sexual Assault Testimony

When There Is No Science to Support Your Opinion

In the course of doing this work, I come across a lot of expert opinions, given by both physicians and nurses. Some of those opinions are well reasoned and supported by current science and clinical experience. Some of those opinions fall into the category I formally call, “making some s*@t up”. Opinions delivered under the latter category aren’t necessarily delivered with the intent to deceive. A lot of times these opinions are simply based on what the professional believes should be true, rather than what research has affirmed.

Much of the erroneous testimony I hear has to do with simply getting the science wrong, or being unfamiliar with the existing body and scope of research. However, there are also some topics of expert opinion that just don’t have any science behind them at all.  If you’re thinking about opining on one of these be aware that you are wading into problematic territory. I just had this conversation with a room full of prosecutors, so I figured I’d also share them with you. Here are a couple of the most common opinions I have heard (repeatedly) that have no science to support them:

You can tell the position the patient was in (or wasn’t in) when she was assaulted by the location of the injuries. Why this is problematic: To date, I am unfamiliar with any research on adults that definitively connects (or rules out) genital injury locations and positioning. While it would be fantastic to have research examining the relationship between position of assault and location of injury in adults, it doesn’t appear to exist. Opining that an injury could never happen based on the way the patient reports she was positioned isn’t one that has any research behind it. Can you say that the injuries present were consistent with the patient’s report of being sexually assaulted ______________ (on her back, from behind, etc.)? Sure. Can you say there is no way she would have had injuries in that location if she was really sexually assaulted __________________ (on her back, from behind, etc.)? I don’t think so.

Patients who engage in/have ever engaged in consensual anal sex are less likely to have injury if they are anally assaulted. Why this is problematic: There are no studies to my knowledge that tell us anything about what consensual anal sex injury looks like, particularly externally. Furthermore, I have not seen a single study that compares anal injury in (anally assaulted) patients who have engaged in prior consensual anal sex with anal injury in patients who have not. If you are tempted to give an opinion that someone who has engaged in prior anal sex would be less likely to have injury after anal assault, I would be very careful. While this may seem like a reasonable assumption to make, it is an unsupported one.

{Bonus opinion: Anal penetration could never be accidental due to the difficulty in penetrating the anus. It takes significant effort to penetrate a person’s anus, and therefore, it is unreasonable to believe anal penetration could ever be accidental. Why this is problematic: like it or not, there’s actually been a study (PDF) done on this topic. It’s a pretty comical study, as it samples predominantly forensic physicians (!) and the results have never been reproduced, as far as I know, but it is out there nonetheless. So the lesson here is, be careful of saying never.}

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5 replies on “When There Is No Science to Support Your Opinion”

I would add that some of you may be thinking, “well I am only testifying to these things because that is what I was taught in my class.” If this is the case, I would add that testimony should never include you needing to say you know something is true because (insert instructor name here)told you so. And finally, instructors should be able to give you the science behind what they are teaching, and students should feel comfortable asking for it.


Great piece Jen. This makes me wonder if we need to even include position of assault as a documentation requirement on our Audit Review Process.

I see where you are saying that there can be no DEFINITE findings just because of one position or another but wondering how important it is for us to document if it really won’t make that much of a difference in one’s testimony since no evidence exists to prove a certain injury exists because the patient was assaulted in a certain position.

What do you all think…is it necessary for documentation???



A long while ago, I did an ‘informal study’ with my patients that had to do with positions. It was quite interesting even though N was small. It was, however, revealing.


I think documenting the details of the assault are important and just because we don’t have the ability to *prove* (or disprove) position based on injury doesn’t mean it isn’t important to potentially document. Consistent statements can still be useful, and if a patient reports the assault in one way to LE and in that same way to us, that in and of itself can be helpful if the case goes forward. I wouldn’t change your documentation practice–just be mindful of what the limits are regarding what we can say we know about this issue.


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