A person can call 911 for help and be the one who leaves the scene in handcuffs. Under Montana law, who made the call does not determine who is arrested. Officers decide based on what they see and hear when they arrive, and where both people appear to have used force, on a statutory test for the predominant aggressor. That test includes self-defense, and it is applied in minutes. This page explains how the decision is supposed to work, what the law of self-defense says, and what to keep. It is part of our Montana Domestic Violence Guide.

If you are in danger now, call 911. The National Domestic Violence Hotline is 1-800-799-7233.

Who Called Is Not the Legal Test

An officer may arrest on probable cause that a person committed an offense (MCA § 46-6-311(1)). When it appears that the parties were involved in mutual aggression, the officer "shall evaluate the situation to determine who is the predominant aggressor," based on six considerations, "regardless of who was the first aggressor" (MCA § 46-6-311(2)(b)):

  1. the prior history of violence between the two people, if available to the officer;
  2. the relative severity of injuries received by each person;
  3. whether an act of or threat of violence was taken in self-defense;
  4. the relative sizes and apparent strength of each person;
  5. the apparent fear or lack of fear between them;
  6. statements made by witnesses.

Making the call is not on the list. The list is not exclusive, so an officer can take the call into account, but nothing in the statute gives it special weight. Each consideration is discussed in predominant aggressor factors.

How the Evaluation Can Go Wrong

The six considerations depend on what the officer can observe in a short time, and several can point the wrong way.

  • Visible injuries. Defensive acts such as scratching, biting, or pushing away can leave visible marks on the other person, while pain, pressure on the neck, or injuries under clothing may show nothing that night.
  • Demeanor. The statute speaks of "apparent" fear. A person who is upset, loud, or has been drinking may not look afraid, and a calm person may be believed more readily.
  • Size. Relative size and apparent strength is one consideration, and it is visible at a glance.
  • History. Prior history counts only "if information about the prior history is available to the officer." An officer may not know it.
  • Who talks. If one person gives a detailed account and the other says little, the report reflects the account that was given.

None of this means officers act in bad faith, and none of it is a comment on the other person. It means an arrest decision made at the door is a first impression. If it appears that both people were aggressors and the officer does not single out one, both may be arrested: see when both people are arrested.

Self-Defense Under Montana Law

A person is justified in the use of force or threat to use force "when and to the extent that the person reasonably believes that the conduct is necessary for self-defense or the defense of another against the other person's imminent use of unlawful force" (MCA § 45-3-102). Three ideas are packed into that sentence: the belief must be reasonable, the threat must be imminent, and the force must be limited to what is necessary.

Two other statutes matter here.

  • The investigation. When an incident appears or is alleged to have involved justifiable use of force, the investigation "must be conducted so as to disclose all evidence, including testimony concerning the alleged offense and that might support the apparent or alleged justifiable use of force" (MCA § 45-3-112).
  • The burden at trial. "When the defendant has offered evidence of justifiable use of force, the state has the burden of proving beyond a reasonable doubt that the defendant's actions were not justified" (MCA § 46-16-131).

The discovery statutes also contain a notice rule. The defense must give the prosecutor written notice of an intention to introduce evidence of justifiable use of force at trial, within 30 days after the arraignment or at a later time the court permits for good cause (MCA § 46-15-323(2)). That is one reason to involve a lawyer early. The defense itself is covered in self-defense in a PFMA case.

Your 911 Call Is Evidence

The call you made was recorded. It can show who asked for help, when, what you reported, and what could be heard in the background. Your own words on it can also be offered against you (Montana Rule of Evidence 801(d)(2)), so it needs to be listened to, not assumed to be helpful. Your lawyer can request it through discovery under MCA § 46-15-322. See the 911 call as evidence.

What to Preserve

  • Your injuries. Photograph them now and again over the next several days, with dates. If you need medical care, get it, and tell the provider accurately what happened.
  • Your phone. Keep call logs, including the 911 call, and all messages and voicemails. Delete nothing, including things you think look bad.
  • Earlier records. Prior reports, medical visits, photographs, or messages that bear on the history between you.
  • Witness names. Write down who saw or heard anything. Give the list to your lawyer. Do not contact witnesses yourself.
  • Your own account. Write it down for your lawyer while you remember it. Mark it as prepared for your attorney and do not share it with anyone else.

More detail is in preserving evidence for your defense.

The No Contact Order Still Applies to You

It can feel backwards, but the order served at arrest binds the person arrested. It is effective for 72 hours or until the first court appearance, where the judge reviews it and can continue it (MCA § 45-5-209(4), (6)). Each contact or attempt to make contact is a separate offense, and "consent of the protected person to prohibited contact is not a defense" (MCA § 45-5-209(8)(b)).

Follow it exactly, even if you believe you are the one who needs protection and even if the other person reaches out first. If you share a home or children, your lawyer can ask the court to address those things. Do not go back to explain, apologize, or collect belongings on your own. See the 72-hour no contact order.

A&M Law defends PFMA charges in Western Montana, and Ashley Hurlbert handles both criminal defense and family law matters. See our PFMA defense page.

This page explains Montana law in general as of the 2025 Montana Code Annotated. It is not legal advice about your specific case.