What Role Does Consent Play in a Sexual Assault Case?

 Posted on January 30, 2026 in Sex Offenses

As of 2026, consent is often the main issue in a sexual assault case, but it is also one of the most misunderstood. Illinois law treats consent as a legal issue, not a personal belief. Small details about timing, words, actions, and the situation can matter a great deal.

Consent is scrutinized especially closely when alcohol is involved, when the people knew each other already, or when the accounts of what happened do not match. Our Naperville, IL sexual assault defense lawyer can explain how consent is defined and whether it legally existed at the time of the allegation.

How Does Illinois Law Define Consent?

Consent is a key part of deciding whether sexual conduct was legal. Problems often arise because people interpret actions, silence, or past interactions differently. The legal system does not rely on assumptions. Instead, it focuses on what each person understood and communicated at the time of the encounter.

Under 720 ILCS 5/11-1.70, consent means a freely given agreement to take part in the act. Specifically, consent must be knowing, voluntary, and freely given. When valid consent exists, Illinois law generally does not consider the incident to constitute sexual assault.

When Is Consent Considered Invalid Under Illinois Law?

Illinois law recognizes situations where consent cannot legally exist. These rules focus on whether a person was able to make a clear and informed decision.

Consent may be considered legally invalid when:

• A person is unconscious, asleep, or unable to understand what is happening.

• A person is impaired by alcohol or drugs to the point that they cannot give meaningful consent.

• Force, threats, or pressure are involved.

When these factors are present, the law may treat the conduct as non-consensual, even if the people involved disagree about what was intended.

Does a Prior Relationship or Past Consent Matter in a Sexual Assault Case?

Illinois courts focus on whether consent existed at the specific time of the alleged incident. Consent must be present during the conduct in question and can be withdrawn at any time. Prior relationships or past consensual encounters do not automatically establish consent for a later interaction. Courts look closely at the words, actions, and circumstances surrounding the alleged incident to decide whether consent was actually given at that moment.

How Do Alcohol and Drugs Affect Consent in Sexual Assault Cases?

Alcohol and drugs often make consent cases more complicated. The issue is not simply whether someone had been drinking. The key question is whether the person could understand what was happening and agree to it.

Courts may look at awareness, balance, memory, and the ability to communicate. A person who has drunk alcohol may still be able to consent. In other cases, impairment may raise serious legal concerns. These situations depend heavily on the facts of the case.

How Is Consent Evaluated During a Criminal Investigation?

Investigators review statements, text messages, social media posts, physical evidence, and witness accounts. They often compare what was said before, during, and after the alleged incident.

Because many cases involve only two people, credibility and consistency become very important. How evidence is handled early can strongly affect how the case moves forward.

Can Consent Be Withdrawn During Sexual Activity?

Consent can be withdrawn at any time. Once consent is clearly withdrawn, continuing the activity may become unlawful.

The key question is whether the withdrawal was clearly communicated and reasonably understood. These issues often depend on context and evidence, not just one statement.

Why Is Legal Representation Important in Consent-Based Cases?

Cases involving consent are rarely simple. They often involve emotional stress, serious accusations, and long-term consequences.

An attorney can review the evidence, challenge assumptions, and make sure the law is applied correctly. Legal guidance is especially important before speaking with police or prosecutors.

Schedule a Free Consultation With Our Naperville, IL Sexual Assault Defense Attorney

At Law Office of Philip R. Nathe, Attorney Nathe brings more than 25 years of legal experience. He previously served as an Assistant State’s Attorney in DuPage County, and he understands the criminal process from both the prosecution and defense perspectives. This allows him to approach cases with balance and insight.

Call 630-416-7600 to schedule your free consultation with a Naperville, IL sexual assault defense lawyer who can help.