9 Ways to Prove Sexual Assault Without Physical Evidence

Investigators don’t always need forensic evidence to prove a sexual assault occurred.

9 Ways to Prove Sexual Assault Without Physical Evidence

This article, originally published in Oct. 2017, was updated in Feb. 2022 to reflect current research and statistics.

If you are a victim of sexual assault, you can call the National Sexual Assault Hotline at (800) 656-4673 or chat online at online.rainn.org for help. Additional resources for victims can be found here


Investigating college sexual assaults is a sensitive process, and to actually prove a sexual assault occurred is an extremely difficult task.

Why can sexual assaults be so difficult to prove or disprove? Unfortunately, there are a number of reasons.

The National Sexual Violence Resource Center estimates 63% of sexual assaults aren’t reported to the police, so just getting the victim to make an official report is the first hurdle, and getting them to follow through in the investigation and adjudication phases can also be a challenge.

One study found that 90% of sexual assaults are committed by someone the victim knows, which can lead to confusion on the part of the victim and reluctance to pursue justice.

According to the U.S. Bureau of Justice Statistics, abuse or assault is:

  • Least likely to be reported if the offender is a current intimate partner or former partner (only 25% of these assaults reported to police)
  • Less likely to be reported if the offender is an acquaintance or friend (only 18-40% of these assaults reported to police)
  • Most likely to be reported if the offender is a stranger (46-66% of these assaults are reported to police)

Additionally, a study from the U.S. Department of Health and Human Services found more than 50% of college sexual assaults involve alcohol, which can affect recall and make the victim fear being punished or feel shame.

Witnesses can also be hard to come by in sexual assault cases generally, and in college specifically because of the prevalence of large, unsupervised parties. Students tend to be at a higher risk at certain times of the year. For instance, more than half of college sexual assaults happen in August, September, October, or November, which is consistent with the first few months of the first semester. 

But experienced sexual assault investigators can find ways around all of these hurdles, and justice can be brought even in sexual assault cases without much initial evidence.

New Title IX changes relating to the college sexual assault investigation process might mean different campuses are using different standards, but every college still has the same goal of keeping their students safe and comfortable.

In May 2020, a serious roadblock for sexual assault investigations was implemented when the U.S. Department of Education implemented a new rule for Title IX investigations. The new rule prohibited decision-makers in sexual misconduct investigations from using evidence or statements from someone who did not participate in cross-examination at a live hearing. This received significant criticism from advocates for sexual assault survivors way believe live questioning could re-traumatize victims and prevent victims from coming forward.

In Sept. 2021, the rule was rescinded, allowing decision-makers to consider evidence from involved parties who did not undergo cross-examinations, including police reports, medical reports, Sexual Assault Nurse Examiner documents, and emails and text messages sent leading up to the alleged misconduct.

Below we give some best practices for campus police to get to the bottom of any sexual assault report, even with limited or no physical evidence. The information is adapted from The Blueprint for University Police: Responding to Campus Sexual Assault, which focuses on giving law enforcement information on handling rape and sexual assault cases.

Trauma-informed practices, which involve recognizing, understanding, and properly responding to the effects of trauma, are becoming more commonplace during police investigations.

The need for trauma-informed investigations is critical since a 2021 survey from Know Your IX,  a survivor- and youth-led advocacy group, found educational disruptions for students who reported their sexual assault to their schools were not from the sexual violence alone, but because of violence exacerbated by schools’ harmful responses to reports of violence.

A study conducted by the Salt Lake County Sexual Assault Response Team (SART) determined applying a trauma-informed approach to sexual assault investigations led to more charges being filed and more successful prosecutions.

When a victim feels supported and protected, they are more likely to participate in an investigation and therefore more likely to provide useful information beyond physical evidence.

Searching for Proof During Sexual Assault Investigations

At first, sexual assault reports can appear to be “He said, she said” scenarios, where there are little investigators can do to corroborate the accused or accuser’s stories. Unfortunately, experienced sexual assault investigators are familiar with these scenarios. 

There can’t always be forensic evidence to work with, but police can still prove sexual assault occurred or didn’t occur with little to no initial evidence, even in cases where there are no witnesses. Here are nine tips:

  1. Practice interview techniques such as victim debriefing and adapt an “information gathering” versus interrogation approach to suspect interviews to gather information. Understand physical descriptions (e.g. tattoos), smells and sounds the alleged victim remembers. Here are more facts and myths on sexual assault that police should know.
  2. Document the specific details of the allegations, all the way down to condom use.
  3. Gather circumstantial evidence during the investigation, such as a sudden behavior change from the alleged victim. Look for dropped classes, withdrawal from sports or social clubs, and a sudden change in academic performance.
  4. Try to establish elements of force, threat, or fear if present from either party.
  5. Look for a serial pattern of behavior from the accused by contacting others who may have been victimized by that person, while being careful not to marginalize the accused.
  6. Conduct an extensive investigation for corroborating evidence including social media and cell phones.
  7. Evaluate the need for a search warrant.
  8. Consider the utility of a pretext phone call to gather evidence from the accused.
  9. Identify and contact any outcry witnesses.

The above information is adapted from The Blueprint for University Police: Responding to Campus Sexual Assault


If you are a victim of sexual assault, you can call the National Sexual Assault Hotline at (800) 656-4673 or chat online at online.rainn.org for help. Additional resources for victims can be found here

9 responses to “9 Ways to Prove Sexual Assault Without Physical Evidence”

  1. 1. can be difficult to disprove
    the accused doesn’t have to disprove it. until the accuser proves it, he is innocent
    imagine a society where accused have to prove they didnt commit a crime

    2. try to establish elements of force, threat, or fear from either party
    this should be pretty self-explanatory why this isnt supposed to happen

    3.if there was a rape, DNA could easily prove if it happened or not.
    even if they used a condom, it will still show. everywhere you go, everything you do, you leave some type if DNA. hair, skin, etc…
    its not perfect. maybe it was consensual at first but if we start with this, we can figure out if it even happened or not. after it has been determined it DID happen, you now at least know the evidence to determine consent exists somewhere

    4.rape is unwanted PHYSICAL sexual contact. everything else is bullshit
    and yes, some people do IN FACT believe “over the internet rape” is a thing
    the fact that needs to be clarified is kinda sad

    • EDIT:
      *the fact that this needs to be clarified*

      • liv says:

        as i read your comment there have been hundreds of women that claimed to have been sexual harassed or assaulted 5 to 20 years ago and have NO PROOF or physical evidence of it and yet the men are being sued and going to jail etc… We live in a society that has allowed women to lie just to get money and has left real women in real life situations that are being beaten and raped for REAL and they can no longer be trusted because we don’t know if it’s real or not… I am a woman and I am disgusted by how many women (ugly women at that) that are lying against rich men just to get money in their pockets. it is sickening

  2. Britany Ricks says:

    I believe it is close to impossible for a victim to be able to come forward about their rape after a couple months…definitely after a year

  3. Millie Hue says:

    It’s relieving to know that there are experts out there that can really help your case even if there are no physical pieces of evidence available. I will share this information with a friend of mine to make her feel better since she really feels like she’s going to lose if ever she files a case. From what I know, one of her colleagues is really creeping her out because the actions and the words that he was using on her is already bothering her. Thanks for the information!

  4. none says:

    Rape is a horrendous experience and though the police won’t follow any leads the victim will be pursued for years by extortionists. It is a dangerous situation and something should be done to make the government prosecute rapists.

  5. Ada says:

    Rape is a horrible experience with out cause and even more frightening not knowing who it is, remarkable there’s hope thank to medical expertise we have a rape kit hope that enough in 2019. were lookin into a new era with a new battle we must be prepared like our dear writer Joyce Meyer our mind are instrument of peace and war.

  6. Jan P says:

    We cannot be a society where people can be ruined and even incarcerated on accusations alone. I personally know a man going through this. The accuser is a spiteful angry teenage girl and even laughs about the fact she doesn’t have to prove anything. She says because of the me too movement, authorities have to believe her. I know both of these people and I don’t believe her for a minute but the man has been ruined financially, spent 3 months in jail and is facing a trial with possible prison time.

  7. Anonymous says:

    I looked this up because I’m going through it right now I came forward with my story and they are working it out right now but the fact that people can protect people like that is discussing to me I get it it’s their job but protecting a rapist and somebody who assaults girls and guys is just wrong.

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