Workplace investigations are critical to maintaining a fair and compliant work environment. Whether it’s an allegation of harassment, discrimination, policy violations, or any other misconduct, an effective investigation requires collecting solid evidence. But what types of evidence can be used? Understanding the different forms of evidence is essential to conducting a thorough investigation that stands up to scrutiny.

Here’s a breakdown of the various types of evidence that can be used in workplace investigations:

1. Documentary evidence

Documentary evidence refers to any written or recorded material that may provide relevant information to the case. This can include:

  • Emails and messages: These are often key pieces of evidence, especially in cases of harassment, bullying, or policy violations.
  • Employment records: Performance reviews, disciplinary records, and personnel files can offer insights into patterns of behavior or relevant past incidents.
  • Company policies and procedures: These documents can help determine whether a policy was violated.
  • Timecards and schedules: These may be useful in verifying claims about attendance, work hours, or whereabouts during an incident.
  • Incident reports: If the issue had been previously reported, these records serve as a historical reference to understand the current complaint.

2. Physical evidence

Physical evidence can include tangible items that are directly connected to the investigation. Some examples include:

  • Surveillance footage: Many workplaces have cameras that can provide visual evidence of incidents such as theft, physical altercations, or inappropriate behavior.
  • Physical objects: In cases of vandalism or damage to property, the physical evidence (e.g., damaged equipment) may support claims.
  • Computer records: Data logs, browsing history, or files accessed or downloaded from company computers can be relevant in cases of misuse of company property or data breaches.

3. Digital evidence

Digital evidence has become increasingly important in workplace investigations, given the rise of technology in the workplace. This includes:

  • Social media posts: Public posts or even private messages shared between employees can provide context or proof of misconduct.
  • Text messages and instant messages: Messages exchanged on platforms like Slack, Teams, or through mobile phones may offer direct insight into communication around the alleged incident.
  • Access logs: If an investigation involves data breaches or misuse of confidential information, access logs can show who accessed what information and when.

4. Testimonial evidence

Testimonial evidence is derived from witness statements and interviews with the involved parties. It’s crucial to gather testimony from various sources to get a complete picture of the situation.

  • Witness interviews: Interviewing employees who witnessed the incident or have knowledge about the matter can provide direct or indirect insights.
  • Accused and complainant statements: Both parties in a workplace investigation need the opportunity to provide their version of events.
  • Expert testimony: In some cases, it might be necessary to consult subject matter experts (e.g., IT professionals for cybersecurity breaches).

5. Circumstantial evidence

Circumstantial evidence does not directly prove misconduct but can imply wrongdoing based on surrounding facts. While it should not be relied upon in isolation, circumstantial evidence can support other types of evidence.

  • Patterns of behavior: If there is no direct proof but a history of similar complaints or incidents, it may indicate a pattern of behavior that supports the allegation.
  • Inconsistent statements: Comparing the statements of the accused, the complainant, and witnesses can reveal inconsistencies that cast doubt on the credibility of certain testimonies.

6. Demonstrative evidence

Demonstrative evidence helps illustrate facts in a more visual or easily understandable way. This type of evidence may not prove a fact by itself, but it aids in explaining the context of the case.

  • Charts and timelines: Creating a visual timeline of events can clarify when incidents occurred and how they align with the provided testimony.
  • Illustrations or diagrams: These can be helpful in explaining spatial relationships or layouts of a workplace, which can be crucial in understanding how an incident took place.

Best practices for collecting and handling evidence in workplace investigations

  • Maintain confidentiality: Keep all evidence confidential and secure to protect the integrity of the investigation.
  • Follow legal and company guidelines: Ensure the collection and storage of evidence comply with applicable laws (e.g., privacy laws) and company policies.
  • Document everything: Record how evidence was obtained and by whom, and keep an accurate chain of custody to maintain credibility.
  • Be objective: Treat all evidence impartially, regardless of which party it supports.

The bottom line

The types of evidence collected in a workplace investigation can make or break a case. By ensuring that your investigation gathers comprehensive and relevant evidence — whether documentary, physical, digital, testimonial, or circumstantial — you’ll build a solid foundation for a fair and thorough process. HR pros should always be mindful of handling evidence correctly to protect the rights of all involved and support sound decision-making.