15 Types of Evidence and How to Use Them in a Workplace Investigation

Evidence comes in many forms and can provide valuable insight during your employee investigations.

Video game company Activision Blizzard, Inc. was in trouble and in the headlines in 2021 due to allegations of a toxic workplace culture, failure to investigate employee harassment complaints, and hiding internal investigations from shareholders. In spring 2022, The California Department of Fair Employment and Housing (DFEH) said "It requested documents and communications pertaining to complaints made by Activision Blizzard employees, and the company's investigations into such complaints. It also sought documents and correspondence related to pay equity analyses, and waivers signed by employees," according to Bloomberg Law.

However, Activision Blizzard refused to hand over the documents, stating that they either didn't exist or were privileged and confidential. As a result, the DEFH has filed a complaint in the California state court alleging that the company has "suppressed evidence and interfered with a government investigation." Actions like this can turn off potential customers, clients, and employees, which is bad news for your bottom line. Don't let this happen to your organization.

Keep track of your evidence with investigation management to protect you whether you're challenged by a whistleblower, angry employee, or regulatory body. Collecting, documenting, and analyzing different types of evidence (like the ones explained below) not only helps you make the right decision in your workplace investigations, but can also keep you out of costly legal and reputational trouble.

Overview of 15 Different Types of Evidence in a Workplace

Understanding the diverse types of evidence is crucial for conducting thorough and fair workplace investigations. Below are the 15 key evidence types, each serving a distinct purpose:

1. Analogical Evidence: Draws comparisons to similar situations for logical reasoning.
2. Anecdotal Evidence: Personal accounts or stories that support or refute claims.
3. Character Evidence: Provides insights into an individual's behavior or traits. ‍
4. Circumstantial Evidence: Suggests conclusions indirectly through related facts. ‍
5. Demonstrative Evidence: Visual aids like diagrams or simulations to clarify points. ‍
6. Digital Evidence: Data from electronic devices, such as emails or logs. ‍
7. Direct Evidence: Firsthand observations directly proving a fact. ‍
8. Documentary Evidence: Written records like contracts, reports, or policies.
9. ‍Exculpatory Evidence: Information that absolves someone of wrongdoing.
10. ‍Forensic Evidence: Scientific data like fingerprints or DNA analysis.
11. ‍Hearsay Evidence: Secondhand information relayed by others.
12. ‍Physical Evidence: Tangible objects, like tools or items, relevant to the case. ‍
13. Prima Facie Evidence: Evidence sufficient to establish a fact unless rebutted.
14. ‍Statistical Evidence: Data and numbers supporting trends or patterns.
15. ‍Testimonial Evidence: Statements from witnesses during the investigation.

For a deeper understanding of how and when to use these evidence types, continue reading below.

1. Analogical Evidence

Analogical evidence, as the name suggests, compares similar things to clarify or explain what has happened and is crucial in investigation management and reporting. For example, say you've previously investigated harassment incidents between Isha and Larry. Even if you don't have hard evidence of harassment, you can use past incidents to assume that Isha's complaint that Larry harassed her (again) is true. Another example: A location of your company in Omaha, Nebraska is a hot spot for employee theft. You plan to open another location in the same neighborhood of the same city with a similar makeup of employees (e.g. gender, race, age, etc.). Based on the incident data from the first location, and the similarities between the two, you should put extra anti-theft measures in place. While not clear enough evidence to use in court, this kind of data can increase credibility by drawing parallels when there isn't enough clear-cut information to prove something in a workplace investigation.

2. Anecdotal Evidence

Anecdotal evidence comes in the form of retellings of events from parties involved in the investigation techniques. In your workplace, the investigation report example might include:

 
• Written complaints or reports
 
• Accounts from the reporter, accused person, and witnesses as told in interviews
 
• Stories shared between an employee and their manager or coworkers

This type of evidence can be written in emails, instant messages, or on paper, or shared aloud in person or over a phone or video call. If you're collecting verbal anecdotal evidence, be sure to record the call or interview to upgrade your Investigation Techniques. Documenting anecdotal evidence ensures that you don't forget any details and can save you met with legal challenges from an employee (such as wrongful termination). Anecdotal evidence isn't used in court but can sometimes help in a workplace investigation to get a better picture of an issue. The biggest problem with this kind of evidence is that it is often "cherry picked" to present only anecdotes that support a particular conclusion. Consider it with skepticism, and in combination with other, more reliable kinds of evidence as a better investigative report example. ‍

RELATED: 48 HR Investigation Questions to Get the Best Information

3. Character Evidence

Character evidence is a testimony or document used to help prove that someone acted in a particular way based on the person's morals, personality, or propensities. While this can't prove that a person's behavior at a specific time was consistent with his or her character, it can be used in some workplace investigations to prove intent, motive, or opportunity. For instance, do Rakim's coworkers describe him as quiet and agreeable? If you then receive a complaint that he yelled at another employee, the behavior goes against the character evidence you have of him. Or, another employee has accused Morgan of stealing cash from her till. Others share that she is often late for her shift, bad-mouths the company, and is rude to customers. This character evidence suggests that she is not committed to her job and may not feel remorse for stealing from the company.

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4. Circumstantial Evidence

Also known as indirect evidence, circumstantial evidence is used to infer something based on a series of facts separate from the fact the argument is trying to prove. It requires a deduction of facts from other facts that can be proven and, while not considered to be strong evidence, it can be relevant in a workplace investigation, which has a different burden of proof than a criminal investigation. For this type of evidence, let's say Manpreet, a woman of Indian descent, was on track for a promotion, but the position was given to Adam, a white man with five years less experience. According to Cornell Law School's Legal Information Institute, examples of circumstantial evidence for discrimination could include different treatment of Manpreet by her manager, hostility toward her, and suspicious timing of the promotion (e.g. not according to your regular promotion schedule). While none of these actions are necessarily discrimination on their own, together, they paint a strong picture that Manpreet was discriminated against in her promotion competition.

5. Demonstrative Evidence

This type of evidence includes items that directly demonstrate a fact and is critical in your workplace investigation techniques. Demonstrative evidence falls into two categories:

 
1. Physical evidence: pieces of evidence you can see and touch, such as a sack of stolen inventory found in the employee's locker
 
2. Illustrative evidence: charts, graphs, photos, models, or recordings, such as a video of an employee harassing another employee

This is one of the most reliable types of evidence to use in your investigation. While there are some cases where demonstrative evidence can be explained away, this is rare. Collect as many pieces as possible to strengthen your investigation techniques and make the right final decision. Do you have trouble hunting down or keeping track of demonstrative evidence during your investigations? Case IQ's centralized platform lets you keep all relevant evidence and information right in the case file. Nothing will be lost or forgotten about, and you'll save time by keeping all your evidence in one place.

6. Digital Evidence

Digital evidence can be any sort of digital file from an electronic source. This includes email, text messages, instant messages, social media posts, files and documents extracted from hard drives, electronic financial transactions, audio files, and video files. Digital evidence can be found on any server or device that stores data, including some lesser-known sources such as home video game consoles, GPS sport watches and other wearable tech, and internet-enabled devices used in home automation. This type of evidence is often found through internet searches using open source intelligence (OSINT).   RELATED: 101+ OSINT Resources for Investigators

Challenges of Digital Evidence

Collecting digital evidence requires a skillset not always needed for physical evidence. There are many methods for extracting digital evidence from different devices and these methods, as well as the devices on which evidence is stored, change rapidly. Investigators need to either develop specific technical expertise or rely on experts to do the extraction for them. Preserving digital evidence is also challenging because, unlike physical evidence, it can be altered or deleted remotely. Investigators need to be able to authenticate the evidence, and also provide documentation to prove its integrity. To combat this challenge, it's crucial to document any uncovered digital evidence immediately. Take a screenshot or screen capture video that clearly shows the time and date. That way, if the accused person deletes the item, you have proof that it was there. Once you have your documentation record (e.g. image or recording), place it into your case investigative case management system right away. With Case IQ not only can you store your records right in the case file, but these actions are added to the case action timeline so you can prove what pieces of evidence you uploaded and when.

7. Direct Evidence

The most powerful type of evidence, direct evidence requires no inference and directly proves the fact you are investigating. The evidence alone is the proof, if you believe the accounts. "Usually," say the experts at Kraut Law Group, "direct evidence will be eyewitness testimony regarding something that was actually observed." Some examples of direct evidence in your workplace investigations could include:

 
• A victim's complaint that a coworker made a discriminatory comment toward them
 
• A witness's account of another employee not abiding by safety protocols
 
• A customer's report that they were harassed by an employee

8. Documentary Evidence

According to the Legal Information Institute, documentary evidence is "a broad term that includes almost anything on paper." However, it also includes documentation of facts found in other forms such as film and audio tapes. In your investigation, types of documentary evidence you might use include:

 
• Ledgers and books (e.g. accounting logs)
 
• Video or audio recordings (e.g. surveillance footage, Zoom meeting recordings)
 
• Photos or screenshot images (e.g. photos of harassment incidents taken by a bystander)
 
• Physical copies or computer printouts of documents, files, records, messages, or emails (e.g. employee records, past case files)
 
• Notes, letters, or other written correspondence (e.g. notes passed between coworkers, termination letters)

9. Exculpatory Evidence

This type of evidence can exonerate the accused person, usually the defendant in a criminal case. Prosecutors and police are required to disclose to the defendant any exculpatory evidence they find or risk having the case dismissed. In the case of workplace investigations, exculpatory evidence is anything you can find that suggests the accused employee didn't commit the bad behavior. For example, Harold accuses Frank of harassing him around noon on March 10th. However, Madeline claims she eats lunch with Frank at that time every day, so he couldn't have been interacting with Harold, otherwise she'd have witnessed it. This information provides an alibi for Frank and can lead you to the conclusion that the harassment didn't take place.

10. Forensic Evidence

Forensic evidence is scientific evidence, such as DNA, trace evidence, fingerprints, ballistics, or other types of investigation reports, and can provide proof to establish a person's guilt or innocence. Forensic evidence is generally considered to be strong and reliable evidence and alongside helping to convict criminals, its role in exonerating the innocent has been well documented. The term "forensic" means "for the courts". The use of this type of evidence in workplace investigations is generally limited to serious cases that may end up in court. For instance, workplace violence, accidents that lead to injury or death, or extreme cases of harassment (especially sexual harassment) might require forensic evidence to be collected and analyzed to reach a conclusion. Forensic evidence (or lack thereof) played a part in the Theranos fraud case. Investigators wanted to access the company's test results database, as blood tests were reported as extremely inaccurate. When they tried to retrieve the database, "the data disappeared." Next, a computer forensics expert then attempted to retrieve the data on Theranos' hard drive, only to discover it was protected by multiple passwords, making it inaccessible. During this part of the investigation, Theranos shut down the facility that housed their database, making that data lost forever to both the company and investigators. The fact that the company would destroy a key tool of their business processes (and potential forensic evidence), coupled with the timing of the shutdown, made federal investigators so suspicious they wrote a filing about it.

11. Hearsay Evidence

Hearsay evidence consists of statements about the incident made by witnesses who are not present. These statements can be written or oral. In a workplace investigation, this type of evidence mostly consists of conversations between parties involved in the incident. Essentially, it's information shared outside of the confines of your formal investigation interviews. For instance, conversations between the victim and the accused person, the victim and their manager, or the accused person and a coworker all fall into the category of hearsay evidence. While hearsay evidence is often not admissible in court, it can be relevant and valuable in a workplace investigation where the burden of proof is less robust than in court.