Types of Evidence That Can Be Used Against You in a Sexual Assault Case

Sexual assault cases are among the most complex criminal cases to prosecute and defend, with a lack of physical evidence often available—and many cases not prosecuted until months after the incident occurred.

Because eyewitnesses are rare in sexual assault cases—the alleged crime is usually committed in private—criminal lawyers must generally rely on the testimony of the victim and defendant. However, forensic, medical, electronic, and video evidence may also be introduced by the Crown prosecution.

Let’s examine more closely the types of evidence that can be used against a defendant in a sexual assault case in Ontario.

Most sexual assault cases boil down to whether consent was provided, based on what the alleged victim and defendant said and did at the time of the incident.

Both parties may agree that sexual contact occurred but frequently disagree on the matter of consent.

Consent is defined as the “voluntary agreement of the complainant to engage in the sexual activity in question.” Consent does not have to be spoken. However, it must be clear, voluntary, and expressed by the words, actions or body language of the person providing it.

It is worth noting that consent must be provided throughout the encounter, not just at the beginning. So, during questioning of the individuals in court, the prosecution and defence lawyers will attempt to elicit responses that prove whether consent was provided throughout, one way or another.

Consent is often pivotal in determining whether a sexual assault crime has been committed—especially when we consider that, in the majority of cases in Ontario and elsewhere, the alleged victim and defendant know each other.

Forensic evidence refers to any physical material, biological sample or trace evidence collected, analyzed, and presented in court to help establish facts in a legal investigation.

In sexual assault cases, forensic evidence can include biological materials such as semen, saliva, blood or hair, as well as trace evidence like fibers, fingerprints or skin cells. This evidence is particularly critical when there is disagreement about whether sexual contact occurred or when consent is in question.

Timely collection of forensic evidence is essential, as biological samples degrade over time and may be lost if there is a delay in reporting or examination. In older cases, the absence or deterioration of such evidence can make prosecution more difficult.

The presence of DNA evidence can significantly strengthen a case by linking a suspect to the crime or excluding an innocent person. This is especially important since research shows that the vast majority of sexual assaults are committed by individuals known to the victim, making forensic evidence valuable in confirming or disproving associations between the parties involved.

Medical records compiled during a patient’s examination, treatment or diagnosis may also be considered a type of forensic evidence in sexual assault cases. For instance, medical reports from an examination after an alleged sexual assault can document any injuries, collect biological samples, and provide evidence of contact.

Such objective documentation of injuries or health conditions can be pivotal in sexual assault cases, corroborating or contradicting statements from the complainant or defendant.

Everything from text messages to posts on social media can be used as digital evidence in sexual assault cases. This may come as no surprise, as people’s lives are increasingly conducted electronically. However, preserving important messages between the subjects of a sexual assault criminal investigation can be problematic, as content can be lost or deleted from servers.

The Canadian courts have ruled that electronic messages between individuals are “third-party records”. This means that they are of a personal nature intended to remain private, so criminal defence or Crown prosecution lawyers need to apply to the court for access to such records.

Digital evidence can be useful in documenting the context and providing background insight into sexual assault cases. However, police investigators often complain that it can complicate cases and make investigations more invasive for victims because retrieving evidence from digital devices can be complex and time-consuming.

Video technology is another source of evidence in sexual assault cases—but it is not without its limitations, too.

Although video surveillance cameras are commonly available to police officers investigating crimes in Ottawa—and they can play an important role in trials—the lack of sound on many of these recordings may leave the defence of an honest but mistaken belief in consent available to the defendant.

Video evidence can also be useful for the defence’s alibi when attempting to prove a defendant’s whereabouts at the time that the alleged offence took place.

A complainant’s past sexual history is not usually relevant in a sexual assault case anywhere in Canada.

When questioning the alleged victim, legal counsel must abide by strict rules. Notably, legislation has banned the admission of prior sexual history evidence in cases where it is intended to support the idea that complainants with a prior sexual history are more likely to have consented and are less believable.

In Canada, approximately one in five sexual assault allegations is classified by police as unfounded or baseless, and some defendants are ultimately acquitted at trial. Therefore, being accused of sexual assault does not mean a conviction is inevitable.

The appropriate defence strategy depends on the specific facts of the case, which should be carefully investigated by an experienced criminal defence lawyer.

Generally, the defence will focus on one of two primary positions:

1. Denial of the alleged act—asserting that no sexual assault occurred; or
2. Honest but mistaken belief in consent—claiming that the accused genuinely, and reasonably, believed that consent was given.

If there is no dispute that sexual contact occurred, and the accused can show that reasonable steps were taken to confirm consent, the defence of honest but mistaken belief in consent may apply. Conversely, if the accused maintains that the sexual activity was entirely consensual, the defence will focus on challenging the credibility or reliability of the complainant’s account.

Because consent in sexual encounters is often implied through conduct rather than explicit verbal or written agreement, experienced defence lawyers may work to highlight inconsistencies or uncertainties in the evidence to raise a reasonable doubt about whether an offence took place.

To understand more about your legal rights and options if you’re facing sexual assault charges in Ontario, speak to a criminal defence lawyer at Affordable Defence in Ottawa during a free consultation.