Eyewitness Testimony is Evidence

Eyewitness testimony is evidence, but is it reliable? I think it is usually reliable enough, but it ultimately has to be understood on a case by case basis, and expertise in relevant areas can greatly help us assess the evidence better. How evidence should function – what counts as good evidence – is an important issue that is not discussed or understood enough. It is greatly an issue of critical thinking and informal logic. In this case it is also highly related to natural science because eyewitness testimony is one of the ways we know about the natural world, and knowing about the natural world can also tell us a lot about how to properly assess the reliability of eyewitness testimony. Eyewitness testimony is an empirical (experience-based) type of evidence.

Let’s consider an example of eyewitness testimony: I painted a picture of bottles, and later saw the painting in my sister’s restaurant. My signature is also on the painting. I let other people know about what happened. This seems like a perfectly legitimate type of evidence. I saw that it is my painting, and it’s no longer in my own home. It would not be appropriate to say I have no evidence. It would not be appropriate to tell me that it is a baseless assertion without evidence.

In a debate, both sides have to provide evidence for their own side, and both sides have the burden of proof. We can’t persuade people to agree with our side without using premises they already agree with. That often also tracks what we should believe well. Our own knowledge and experience can be different from those on the other side, and disagreement can be reasonable as a result. Eyewitness testimony is one way experience itself can enter a debate, and it should not be said to be a mere assertion without evidence.

How does evidence and debate function regarding the principle that people are innocent until proven guilty? This is a principle of the court of law in the United States, and I think it is a good thing that we have that principle. Even so, a court of law is not the same thing as good reasoning in all contexts, and this principle can be misused in ordinary life. We will often have a good reason to believe someone is guilty of a crime before we send them to court to prove their guilt. We might know someone is guilty and know we can’t prove it in court. If someone hurts me and I was there to see it happen, it would not be appropriate to tell me, “You can’t prove it, so you are wrong that they hurt you!” Nonetheless, it can be reasonable to be undecided or to assume innocence until there is sufficient evidence of guilt – a nuanced concept that can be better understood with expertise in the relevant areas.

What about accusations given by eyewitness survivors of sexual assault? Should we trust them? Would you trust your sibling, parent, child, or best friend when they tell you that someone hurt them? I think we generally would and should. Being a witness is good evidence in some cases. A stranger should probably be trusted less, but their accusations are also evidence.

I think we should keep in mind at least four common additional considerations that can add credibility to an eyewitness accusation:

One, when the perpetrator is known by the witness, then false identification is unlikely.

Two, an eyewitness accuser of sexual assault will likely be harmed even more by speaking out and is unlikely to have a relevant personal benefit from the accusation. False accusations are more likely when they are done for self-interested reasons, but those reasons are almost non-existent for the most part regarding sexual assault or rape. We also know that survivors often (and perhaps usually) face retaliation – harassment, abuse, death threats, etc. (More info.) Conviction rates for these crimes are low, and we know that even when guilt of rape or sexual assault is proven in court, the penalty is often very small. (More info.)

Three, false accusations of rape and sexual assault are also known to be very rare, and ignoring that fact is a mistake in my view. (More info.)

Four, multiple similar accusations provide stronger evidence.

Consider those who ignore these considerations and insist that we should not trust eyewitness survivors who speak out about sexual assault by saying, “A person is innocent until proven guilty!” Imagine Martha tells her husband, Dave, that she was sexually assaulted by Roger, who was her friend the previous month. One day Martha is out of town, Dave needs to hire a babysitter to watch their children, and Roger applies for the job. Roger seems perfectly qualified in all ordinary respects and he has more experience than any other candidate. Is it okay for Dave to hire Roger for the job? That would seem outrageously wrong to me.

There are many now insisting that eyewitness testimony is unreliable. That could be true in certain contexts, but I think it is usually good enough in everyday life. Expertise in the relevant areas can greatly assist our ability to assess the reliability of eyewitness testimony.

Information about the potential unreliability of eyewitness testimony can be found here.