Case preparation
Build an evidence matrix for criminal discovery review
Move from a folder of files to specific questions about each charge, with evidence another reviewer can open and check.
On this page
An evidence matrix for criminal discovery connects each charge or review question to the source material that may support it, conflict with it, or leave it unresolved. Use one row per question, precise page or timestamp references, and a separate next-action field. The goal is a review another person can follow, not a score that decides the case.
Confirm what you are organizing around
Begin with the current charging document. Record the count, its wording, the source page, and the version reviewed. Distinguish an allegation in a police narrative from a filed count; do not turn every offense mentioned in discovery into a current charge.
The responsible lawyer should verify the applicable legal requirements and current references for the jurisdiction. Keep that legal work separate from the factual account in each source. A report's use of a legal label is not a substitute for examining the underlying facts.
Use columns that preserve the reasoning
| Column | What to enter |
|---|---|
| Charge or review question | The count and a specific factual question the team needs to examine. |
| Source location | Original file/version, page or elapsed recording range, and a link where available. |
| Account or observation | Who says it, what is directly observable, and whether the entry is a quote or summary. |
| Potential support or conflict | How this source relates to the question, without declaring the question resolved prematurely. |
| Coverage and next action | What was not reviewed, what is missing, who will follow up, and the current review status. |
A worked fictional example
Suppose a fictional charging document identifies a count arising from an encounter outside a building. This example deliberately uses review questions rather than supplying statutory elements. It illustrates organization, not the requirements of a particular offense.
| Review question | Source and account | Current assessment | Next action |
|---|---|---|---|
| Who was present at the doorway? | Report R-01 p. 4 identifies the defendant. Interview I-02, elapsed 00:07:10–00:07:39, says the witness saw someone from across the street. | The sources describe different observation conditions. Identity remains a question for review. | Check the witness’s surrounding description and any available image evidence. |
| What happened before contact? | Camera V-03 begins after the parties are already together. Report R-01 p. 5 describes the earlier approach. | The camera does not cover the earlier approach; that is a coverage gap, not a contradiction. | Locate any earlier recording or another account. |
| What does the quoted reply establish? | Interview I-02, elapsed 00:08:05–00:08:22: “I couldn’t see his hands from there.” | This quote describes the witness’s limited view. It does not establish what the hands were doing. | Keep the limitation with the quote when using it in working notes. |
Separate disagreement, ambiguity, and missing coverage
Two sources may disagree about the same event. They may also discuss different moments, use different clocks, or reflect different viewpoints. Record the actual difference before labeling it a contradiction. Check the surrounding passage and the identity of the speaker.
Likewise, “not found in the files reviewed” is a statement about the review scope. It does not establish that evidence does not exist. Keep the inventory and unreadable or unprocessed files available alongside the matrix.
Update the affected rows when discovery changes
When another production arrives, identify which existing questions it may answer. Add its receipt date and source version, then revisit those rows. Preserve the earlier entry and explain the change rather than silently replacing a conclusion.
Before a handoff, have the next reviewer reopen one source from each important row. A matrix is useful only if its entries remain connected to evidence. Use the statement-location workflow for stable references and the AI verification guide when a machine generated the initial finding.
Use the matrix to direct the next review
Finish a working session with explicit next actions: check a quotation, locate another recording, resolve a source version, or ask the lawyer to assess significance. Avoid a single “complete” label that hides unfinished work. For recordings, the body-camera review guide shows how to keep report and recording observations separate.
Common questions
What is an evidence matrix in criminal discovery review?
It is a working table connecting a charge or review question to the relevant source material, apparent support or conflict, remaining gaps, and the next review action. It organizes the review; it does not decide legal sufficiency.
What should go in an evidence matrix?
Include the charge or question, the source file and page or timestamp, whose account it is, the observation, review status, and follow-up. Keep missing material separate from evidence that contradicts an account.
Can one source support more than one charge?
A source may be relevant to several questions. Link the same stable source reference to each relevant row and explain its role, rather than copying an unsupported conclusion across counts.