Overview: civil vs. criminal claims

Evidence you need will depend on whether the matter is a criminal prosecution or a civil tort claim. Criminal assault is prosecuted by the state and requires proof beyond a reasonable doubt. A civil assault (a tort) is decided by a judge or jury using the lower preponderance of the evidence standard (more likely than not).

Oregon’s criminal statutes covering assault and related offenses are in Oregon Revised Statutes chapter 163. See the chapter for statutory definitions and degrees of assault: ORS Chapter 163 (Crimes).

What a plaintiff (civil) or prosecutor (criminal) must prove

Civil assault (common law) usually requires showing:

• An intentional act by the defendant;
• That the act reasonably caused the plaintiff to fear imminent harmful or offensive contact;
• No need for physical contact (that would be battery); the apprehension alone can support assault.

Criminal statutes define specific offenses and degrees. Generally, prosecutors must prove the defendant intentionally, knowingly, or recklessly caused physical injury or placed someone in fear of imminent physical injury, depending on the statute and degree charged. Consult ORS Chapter 163 for the text that applies to specific charges.

Types of evidence that commonly prove an assault claim

Courts accept many kinds of proof. The stronger and more consistent the evidence, the better your chance to prevail.

1. Victim testimony: First-person account of what happened, what was said, and how the victim felt. Include the timing, location, and any threats. Jurors often weigh credibility of live testimony heavily.
2. Witness statements and testimony: Independent witnesses who saw or heard the incident (bystanders, coworkers, neighbors). Get their contact information and written statements if possible.
3. Police reports: The initial report, 911 call records, and officer observations. Police reports are not conclusive proof of guilt but provide contemporaneous documentation and investigative leads.
4. Photographs and video: Photos of injuries, torn clothing, damaged property, scene conditions, and timestamped video (surveillance, doorbell, phone) are powerful. Preserve originals and metadata.
5. Medical records: ER notes, physician exams, imaging, and nurses’ observations that document injuries and treatment. These show objective physical harm and timelines.
6. Text messages, emails, and social media: Threatening messages, admissions, or planning messages that show intent or corroborate the timeline.
7. Audio recordings: 911 calls, voicemails, or other recordings that capture threats or events. Check admissibility rules and state laws about recording conversations.
8. Physical evidence: Clothing, weapons, blood, or other items from the scene. Preserve chain of custody and avoid cleaning or discarding evidence.
9. Expert testimony: Medical experts, forensic examiners, or crisis counselors can explain injuries, likely causes, or the impact on the victim.
10. Prior threats or pattern evidence: Prior abusive messages or threatening conduct may be relevant to intent or motive (subject to rules on character evidence).
11. Timeline documentation: Calendars, receipts, timestamped photos, or other records that place the parties at the scene or establish sequence of events.

How much evidence is enough?

For criminal cases, the prosecutor must prove every element beyond a reasonable doubt. That requires strong, often multiple, pieces of corroborating evidence. In civil cases, the plaintiff needs to prove the claim by a preponderance of the evidence (more likely than not). Civil claims sometimes succeed with fewer or weaker pieces of evidence than a criminal prosecution would require.

How to preserve and collect evidence

• Seek immediate medical attention and keep records of care.
• Call police and ask for an incident or case number. Request a copy of the report.
• Take photos and videos of injuries and the scene as soon as possible. Keep originals and preserve metadata.
• Preserve clothing and other physical evidence in paper bags (not plastic) to avoid degradation.
• Write down everything you remember while it’s fresh: times, words, actions, witnesses.
• Collect names and contact information for witnesses and ask them for written statements if they are willing.
• Save texts, emails, voicemails, and screenshots. Back them up and avoid altering them.
• Preserve surveillance or doorbell video by asking property owners or businesses to save footage and to provide a copy or written confirmation that they retained it.
• If possible, consult an attorney early so evidence can be collected with legal strategy and chain-of-custody rules in mind.

Defenses and context to consider

Defendants may claim self-defense, defense of others, consent, mistaken identity, or lack of intent. Evidence you gather should also anticipate those defenses—timing, witness corroboration, and context matter. In criminal cases, the prosecutor must disprove a lawful self-defense claim beyond a reasonable doubt.

Next steps if you have an assault claim

1. Preserve evidence immediately (medical records, photos, messages).
2. Report the incident to police if appropriate and request report copies.
3. Talk to an attorney experienced in Oregon assault law for guidance on criminal or civil options and evidence collection.
4. Consider civil protection orders if you fear further harm; local court clerk or an attorney can explain the process.