Building an Evidence-to-Allegation Matrix in a Workplace Investigation

A workplace investigation can become complicated much faster than expected. A complaint that starts with one allegation may eventually involve several witnesses, dozens of documents, conflicting accounts, text messages, emails and events stretching over months.

By the time interviews are complete, the investigator may understand the case very well but still have difficulty answering a deceptively simple question: What evidence actually relates to each allegation?

That is where an evidence-to-allegation matrix becomes useful. It does not decide the case. It does not replace the investigator's judgment. Its purpose is much simpler: to stop the investigation from becoming a collection of information that no longer has a visible structure.

Start with the allegations as they are actually being investigated

Before building the matrix, make sure the allegations themselves are reasonably clear.

“Harassment” is usually too broad to be useful as a single investigative question. A more workable allegation might identify a particular statement, action, decision or event, with enough time and context to understand what is actually being examined.

Breaking the matter into understandable allegations does not mean prejudging what happened. It simply gives the evidence somewhere to attach. If the allegations remain vague, the evidence matrix will be vague as well.

Give each allegation its own space

For each allegation, create a place to identify the information that may bear on it. That might include witness testimony, documents, emails, messages, photographs, policies, records, access data or other material.

Some evidence will relate to more than one allegation. That is fine. The point is not to force every piece of information into one box. The point is to make the relationships visible.

A message thread might support the timing of one allegation while providing context for another. The matrix should show both connections.

Do not confuse relevance with support

One of the easiest mistakes is to treat everything associated with an allegation as evidence supporting it.

That is not how investigations work. Some evidence supports an allegation. Some weighs against it. Some provides context without clearly favoring either side. Some raises a new question. And some turns out not to matter very much at all.

Those are four different pieces of information. The matrix helps the investigator see them together without pretending they all point in the same direction.

Record what an item establishes, not what you hope it establishes

Suppose a calendar record shows that the complainant and respondent were both scheduled to attend a meeting. That may help establish opportunity. It does not establish that the alleged statement was made.

Similarly, an email sent after an incident may show what the sender reported at that time. It does not automatically establish that every statement in the email is accurate.

Writing down what an item actually establishes is a useful discipline. It keeps the investigation closer to the evidence and farther from assumptions.

Use the matrix to expose gaps

One of the best uses of an evidence-to-allegation matrix is discovering what is missing.

Imagine reviewing an allegation and finding that the entire column depends on one witness account. That does not mean the witness is wrong. It does tell the investigator that corroboration may deserve additional attention.

Perhaps there is a document that has not been requested. Perhaps another person was present. Perhaps an interview needs follow-up. Perhaps no additional evidence exists and the case will ultimately depend heavily on credibility.

The matrix does not solve that problem. It makes the problem harder to overlook.

Contradictions belong in the matrix

Conflicting evidence is not clutter. It is part of the investigation.

If one witness remembers the meeting occurring on Tuesday and another says Thursday, record the conflict. If the calendar indicates Wednesday, record that too.

Do not quietly choose the version that fits the current theory and leave the rest somewhere else in the file. Contradictions often tell the investigator where additional work is needed.

Keep credibility separate from convenience

A matrix can make certain witnesses appear more important simply because their names occur repeatedly. That is not a credibility assessment.

Credibility requires judgment about the particular circumstances of the investigation. Factors may include opportunity to observe, consistency, corroboration, motive, plausibility and other considerations relevant to the case.

The matrix helps organize those inputs. It should not reduce credibility to a score produced by counting boxes.

Update the matrix as the investigation changes

Workplace investigations rarely stay exactly as they looked on day one.

A witness may raise another allegation. A document may change the apparent chronology. An interview may show that the original allegation needs to be stated more precisely.

When the scope legitimately changes, update the structure. Do not keep forcing new evidence into an allegation that no longer accurately describes the issue being investigated. At the same time, preserve a record of material changes so it remains possible to understand how the investigation evolved.

Use the matrix before writing findings

Before reaching a determination, review each allegation on its own.

What evidence supports it? What evidence weighs against it? What remains uncertain? Are there conflicts that were never resolved? Has important evidence been considered because it actually relates to this allegation, or simply because it existed in the file?

That review can expose weak reasoning before it reaches the final report.

When that review is complete, see Structuring the Final Workplace Investigation Report for a disciplined way to carry the allegation, evidence, analysis, and finding into the report.

An evidence-to-allegation matrix is not sophisticated because it uses a table. It is useful because it forces the investigator to maintain a visible relationship between the question being investigated and the information being used to answer it.