The 8-Step Workplace Investigation Process in Ontario: A Complete Guide

A workplace investigation is a structured process, not a reaction. When conducted deliberately and thoroughly, it resolves conflict, protects employees, and shields your organization from legal exposure. When rushed or incomplete, it creates more problems than it solves.

This guide walks you through the 8-step process that defines a defensible, OHSA-compliant investigation in Ontario.

If you're unsure whether a situation requires an investigation at all, see Am I Legally Required to Investigate?. It covers your legal obligations under OHSA Section 32 and the Human Rights Code.

Step 1: Receive and Document the Allegation

The investigation begins the moment an allegation reaches anyone in management or HR.

What to do:

• Listen and record. When an employee reports a concern, listen without judgment. Take contemporaneous notes—jot down the date, time, who reported it, and a summary of what was reported.
• Don't investigate on the spot. This is not the time to ask follow-up questions or promise immediate action. Thank the person for coming forward and assure them the concern will be taken seriously.
• Separate the reporter from the respondent. If possible, ensure the complainant and respondent do not work in immediate proximity during the investigation. Separation reduces tension and allows people to work without fear.
• Document the allegation in writing. Create a formal record: Who reported it? When? What specifically was alleged? To whom was it reported? This becomes your investigation's starting point.

Common missteps:

• Telling the employee "we'll look into it" and then doing nothing for weeks
• Allowing the respondent to know the identity of the complainant before the respondent is interviewed
• Taking only verbal reports and skipping written documentation
• Delaying the documentation process; by the time you write it down, details are fuzzy

Timeline: Complete within 24 hours of receipt.

Step 2: Assess and Plan the Investigation

Before you interview anyone, you need a plan. If you're not sure what legal obligations apply to your situation, see OHSA Section 32: Employer Investigation Obligations to understand your regulatory framework.

What to do:

• Define the scope. What exactly is alleged? Is it isolated conduct or a pattern? Are multiple people involved? Does the allegation involve a protected ground under the Ontario Human Rights Code? Is criminal conduct alleged? Scope shapes your entire investigation.
• Identify the investigator. Who will conduct this? An internal HR person, an external HR investigator, or counsel? Independence matters. If the investigator has a relationship with either party, that's a problem.
• Assess legal exposure. Does this allegation trigger OHSA compliance? Is HRTO (Human Rights Tribunal of Ontario) exposure present? Should your lawyer be involved now? Assess early.
• Create a witness list. Who must be interviewed? The complainant, the respondent, witnesses to the conduct, people with knowledge of context (prior complaints, workplace dynamics). Cast a wide net; you can narrow it later.
• Establish a timeline. When will you start? When will you finish? What are the milestones (first interviews, document collection, draft findings, final report)? Commit to dates and stick to them.
• Plan for privilege. If your lawyer is involved, establish how the investigation will be conducted to preserve work product privilege. (Generally: have HR conduct the investigation, and have counsel advise the investigator.)

Common missteps:

• Skipping the planning phase and jumping straight to interviews
• Choosing an investigator with a conflict of interest
• Interviewing some parties but not others
• Not assessing whether legal counsel should be involved

Timeline: Complete within 48 hours of allegation; no investigation begins without a plan.

Step 3: Notify the Parties and Preserve Evidence

Before interviews begin, parties must be notified and evidence must be preserved.

What to do:

• Notify the complainant. In writing, confirm that you've received their allegation and that an investigation will be conducted. Outline the investigation process, timeline, and their role. Assure them of anti-retaliation protection.
• Notify the respondent. In writing, inform them that an allegation has been made about their conduct. Provide enough detail that they understand what is alleged (without naming the complainant if privacy is important). Give them a deadline to submit their written response if they wish. They should also understand anti-retaliation protection.
• Preserve evidence. Issue a litigation hold notice to relevant parties: preserve all emails, text messages, documents, and records related to the allegation. Specify the retention period. Failure to preserve evidence when you have notice of a dispute can be fatal to your defense.
• Set confidentiality expectations. Tell all parties that the investigation is confidential. Information should not be discussed with coworkers, and discussing the investigation outside the investigation team may result in discipline.
• Identify interim measures if needed. If there is risk of retaliation, violence, or evidence destruction, implement interim measures immediately: separate the parties, modify schedules, restrict access, assign a chaperone for interactions.

Common missteps:

• Notifying the respondent before interviewing the complainant (the respondent might coach other witnesses)
• Not preserving evidence until after interviews (evidence disappears)
• Allowing complainant and respondent to discuss the investigation (contamination and retaliation risk)
• Failing to implement interim measures when safety or retaliation risk is high

Timeline: Notifications sent and interim measures in place within 24-48 hours.

Step 4: Conduct Complainant Interview

The complainant's account is your starting point. This interview sets the foundation.

What to do:

• Schedule a private, comfortable setting. The complainant should feel safe. A private office with a closed door, no interruptions, is appropriate.
• Explain the process. Start by describing how the investigation will unfold, what will happen with their information, and what the next steps are.
• Get the detailed account. Ask open-ended questions first: "Tell me what happened." Then follow up with specifics: "When did this occur?" "Where?" "Who witnessed it?" "What did you observe?" "What was said?" Take detailed notes or record (with permission).
• Ask about impact. How has this conduct affected them? Their work? Their health? This matters for assessing severity and remedial measures.
• Ask about witnesses. Who did they tell at the time? Who might have observed? This builds your witness list.
• Don't make promises. Don't promise a specific outcome or timeline. Say: "We'll investigate thoroughly and reach conclusions based on evidence."
• Assure confidentiality and anti-retaliation. Explicitly state that information will be shared only on a need-to-know basis and that any retaliation will not be tolerated.
• Provide contact information. Give them a way to reach the investigator if they think of additional information.

What not to do:

• Don't be hostile or skeptical. The complainant may be telling the truth; your job is to find out, not prejudge.
• Don't rush. This interview may take 45 minutes to 2+ hours depending on complexity.
• Don't promise confidentiality you can't keep. If findings must be shared with the respondent or leadership, be honest about that.
• Don't make notes and then rewrite them later from memory. Contemporaneous notes are stronger.

Timeline: Conduct within 48-72 hours of receiving the allegation.

Step 5: Conduct Respondent Interview

The respondent deserves an opportunity to respond to allegations. This interview must be fair and thorough.

What to do:

• Schedule with notice. Give the respondent notice of the interview and an opportunity to prepare. "We have an allegation about your conduct. We'd like to meet on [date] at [time] to hear your account."
• Outline the allegation clearly. Describe what is alleged without unfairly prejudicing them. Example: "You are alleged to have raised your voice, used derogatory language, and created a hostile environment for [complainant] on [date]."
• Allow them to respond fully. Ask: "What is your account of what happened?" and "Do you disagree with any part of what was alleged?" Let them speak without interruption.
• Ask clarifying questions. "When did you last interact with [complainant]?" "What was your intent?" "Were there other witnesses?" "Is there documentation that supports your account?"
• Assess their credibility. Are they evasive? Defensive? Do they take responsibility or deflect? This informs your findings.
• Offer written response option. If they prefer, allow them to submit a written response within a specified timeframe (e.g., 3-5 business days).
• Explain next steps. Tell them when they can expect findings and what will happen after.

What not to do:

• Don't ambush them. Notice and opportunity to prepare are fair, and they're essential to defensibility.
• Don't present the complainant's allegations as fact. Characterize them as allegations pending investigation.
• Don't allow the respondent to bully or dominate the interview. If they become hostile, pause and reset: "I understand this is stressful. Let's take a break."
• Don't make promises about the outcome. "I don't know what the findings will be. That depends on the evidence."

Timeline: Conduct within 3-5 business days of the complainant interview (allows respondent time to prepare).

Step 6: Conduct Witness Interviews

Witnesses provide critical context. Their accounts strengthen or weaken the complainant's and respondent's credibility.

What to do:

• Interview all identified witnesses. If someone witnessed the conduct or has relevant knowledge, they must be interviewed. Don't pick and choose; interview everyone.
• Ask consistent questions across witnesses. While questions may be tailored, all witnesses should be asked about the same key facts. This allows you to assess consistency.
• Be neutral. Don't hint at your theory. Let witnesses tell their account independently.
• Ask about timing and details. "What did you see?" "What did you hear?" "Who was present?" "When did this occur?" Get granular.
• Assess credibility. Did the witness have a good view? Were they close to the conduct? Are they credible? Do they have a motive to lie?
• Document everything. Contemporaneous notes are critical. If you can record (with permission), even better.
• Protect witness anonymity if requested. Some witnesses fear retaliation. If they ask for confidentiality, honor that (within limits—you may need to reveal them to the respondent for fairness).

What not to do:

• Don't skip difficult witnesses. If someone might have relevant information, you must attempt to interview them.
• Don't coach witnesses. "Tell me what you know" is good. "Tell me whether you saw him raise his voice" is leading and creates a credibility problem.
• Don't allow witnesses to discuss their interviews with each other. This contaminates evidence.
• Don't assume silence means nothing happened. A witness who says "I didn't see anything" is still a witness.

Timeline: Complete all witness interviews within 7-10 days of the complainant interview.

Step 7: Gather and Analyze Evidence

Documents and records corroborate or contradict the accounts you've heard.

What to do:

• Collect relevant emails and messages. Request emails between the parties, text messages, Slack messages, and any written communication. Dates, timing, and tone matter.
• Gather organizational records. Shift schedules, attendance logs, meeting minutes, prior complaints, performance reviews, disciplinary records. These show context.
• Obtain policies and standards. What does your code of conduct say? What does your harassment policy require? What policies govern the conduct in question?
• Review prior complaints. Is there a history? Did this respondent have prior allegations? Did this complainant file prior complaints? Pattern evidence matters.
• Obtain any other documentation. Work product, project notes, witness statements, training records—anything that illuminates the context.
• Analyze the evidence. What does it support? What contradicts? Does it corroborate the complainant? The respondent? Neither?
• Assess credibility against evidence. If the complainant said the conduct happened on [date] but your email evidence shows the respondent was not at work that day, that's a credibility problem. Document these inconsistencies.

What not to do:

• Don't ignore inconvenient evidence. If something contradicts your theory, include it in the analysis.
• Don't manufacture evidence. Only use documents that are genuine and relevant.
• Don't rely exclusively on one form of evidence. The strongest investigations use multiple forms: testimonial (interviews) and documentary (emails, records).

Timeline: Parallel to interviews; complete within 14 days of receiving the allegation.

Step 8: Reach Conclusions and Prepare Findings Report

This is where you synthesize everything: interviews, witness accounts, documents, and credibility assessments.

What to do:

• State your findings clearly. For each allegation, determine: Substantiated (supported by evidence), Unsubstantiated (evidence does not support), or Inconclusive (insufficient evidence to decide). Use the civil standard of "balance of probabilities" (more likely than not).
• Document your reasoning. Why did you reach this conclusion? What evidence supported it? If you disbelieved someone, why? This reasoning is essential to defensibility.
• Address credibility. Explain which accounts you found credible and why. Did demeanor matter? Did the evidence corroborate or contradict? Be specific.
• Consider context. Is there a power imbalance between the parties? Prior history? Organizational culture issues? Context informs findings.
• Recommend remedial action. If findings are substantiated, what corrective action is appropriate? Discipline? Training? Policy change? Monitoring? Be proportionate.
• Draft a report. Your findings report should include: allegation summary, investigation process, witness list, evidence reviewed, findings for each allegation, reasoning, and recommendations. This is your defensibility document.
• Allow respondent to respond to draft. If you found allegations substantiated, give the respondent an opportunity to respond to the draft findings. Fair process requires this.
• Finalize the report. Incorporate any response from the respondent, refine findings if warranted, and finalize.

What not to do:

• Don't leave findings vague. "Maybe it happened" is not a finding. Be decisive.
• Don't skip reasoning. "I found it substantiated" with no explanation invites tribunal review.
• Don't ignore the respondent's response to draft findings. If they raise legitimate points, adjust. If not, explain why you're not changing the finding.
• Don't recommend discipline without proportionality. A first-time minor breach and a pattern of serious misconduct deserve different responses.

Timeline: Draft findings within 30-45 days; finalize within 60 days.

Post-Investigation: Implementation and Monitoring

The investigation doesn't end with the report. You must act on it. For guidance on what happens after findings are finalized and how to manage remediation and follow-up, see What Happens After a Workplace Investigation.

What to do:

• Communicate findings to complainant and respondent. In writing, inform both parties of findings and remedial action. Be clear but not unnecessarily detailed.
• Implement remedial action. If discipline was recommended, apply it. If training was recommended, schedule it. If monitoring was recommended, establish the monitoring protocol.
• Document implementation. Keep records of when and how remedial action was carried out.
• Monitor compliance. If the finding was substantiated, monitor the respondent's behavior. Is the conduct stopping? Are there further incidents?
• Protect against retaliation. Watch for any adverse action against the complainant post-investigation. Any schedule change, demotion, or isolation can be characterized as retaliation.
• Follow up with complainant. After remedial action, check in with the complainant. Are they comfortable returning to the team? Are they safe?
• Escalate if needed. If misconduct continues or retaliation occurs, escalate the response. More severe discipline, role change, or termination may be warranted.

Timeline: Remedial action within 7-14 days of finalizing the report; monitoring ongoing.

Key Considerations for Ontario Investigations

OHSA Section 32.0.7 Compliance

Ontario's OHSA Section 32.0.7 requires prompt, reasonable investigation of allegations of workplace violence and harassment. The 8-step process above reflects that standard.

Ontario Human Rights Code

If the allegation involves discrimination or harassment on a protected ground (race, gender, disability, sexual orientation, family status, etc.), you're subject to Human Rights Code obligations as well as OHSA. The investigation must be fair and thorough to withstand HRTO scrutiny.

Privilege Considerations

If your lawyer is involved, ensure investigation is structured to preserve work product privilege. Generally, have HR conduct the investigation with legal counsel advising; don't have counsel run the investigation itself.

Timing Matters

Investigations that extend beyond 90 days invite questions about whether the employer took the obligation seriously. Stay on schedule.

Documentation is Everything

You will be asked to defend this investigation. Your written record—interview notes, evidence list, analysis, findings, and reasoning—is your defense. Invest in documentation.

Independence Strengthens Credibility

An external, neutral investigator carries more weight than an internal person, especially if conflicts exist. If concerns about internal investigator independence arise, consider engaging external counsel.

When to Engage Professional Investigators

If an investigation is complex, involves senior leadership, has legal exposure, or requires independence, engage external investigators early. 1205 Consulting can:

• Conduct the investigation from start to finish
• Advise your team on investigation planning and process
• Work alongside your legal counsel to preserve privilege
• Provide a neutral investigator when internal conflicts exist
• Prepare tribunal-ready documentation and findings
• Support remedial action and compliance monitoring

A well-conducted investigation resolves conflict, protects employees, and demonstrates to regulators that your organization takes its OHSA and Human Rights Code obligations seriously.

For a comprehensive overview of workplace investigations from investigation selection to documentation standards, see The Complete Guide to Workplace Investigations in Ontario.

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Ready to conduct a defensible investigation? Contact 1205 Consulting for a free scoping call. We'll help you plan, conduct, and document an investigation that protects your organization and resolves workplace conflict fairly.

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1205 Consulting specializes in workplace investigations under Ontario's OHSA and Human Rights Code. Our investigators are experienced in conducting fair, thorough, tribunal-ready investigations that resolve conflict and protect your organization.