How to Build an Evidence Timeline

Key Takeaways

The method	Build a timeline of events and documents so gaps and contradictions show up before you publish.
Why it matters	Readers (and editors) trust a story that can show what was knowable on which date.
On Gnosis	Pin dated exhibits on the Evidence Board; Premium unlocks the full board map.

A pile of PDFs is not an investigation until you can say what happened in order. An evidence timeline is a dated list of events and the records that support each date — built so a skeptic can walk the same path you did. This is Methods practice for indie investigators, not a software tutorial.

Separate event time from discovery time

Write two columns mentally: when the underlying fact occurred (meeting date, filing date, transaction date) and when you obtained the document. Publish the event timeline; keep discovery notes in your working file. Mixing “I downloaded this Tuesday” with “the contract was signed in March” confuses readers and hides holes.

One row, one checkable unit

Each row should be a single claim fragment: date, what happened, exhibit link or ID, and credibility label (primary / reported / opinion / unverified). If a row needs three documents to make sense, split it. Narrow rows make contradictions visible — two filings that cannot both be true on the same day.

Leave the gaps visible

Blank stretches are findings, not failures. Mark “no public record found for Q2” as honestly as you mark a contract. When you FOIA or docket-search later, you are filling a named gap, not wandering.

Do this next on Gnosis

Use the free Investigator Starter Kit to sketch the claim and first exhibits, then open Gnosis and pin dated sources to your investigation. Premium unlocks the full Evidence Board on Pricing.

More Methods: Investigation Methods hub.

Choose a resolution that matches the claim

Day-level timelines fit most public-records stories. Hour-level timelines matter for breaking events and some criminal process stories. Month-level summaries hide the contradictions you need. Pick the finest grain you can sustain with exhibits, then coarsen only for overview graphics — never for the working sheet that drives FOIA and interviews.

Include “negative space” rows: dates you searched and found nothing. Those rows justify the next request and protect you from hindsight bias (“we always knew X”). When a late-breaking document arrives, insert it by event date, not by the day it landed in your inbox.

Cross-check like an auditor

When two primaries disagree on a date, escalate: which document is certified, which is a draft, which is a press summary? Do not average the dates. Flag the conflict on the timeline and in the published piece until resolved. Reported sources that paraphrase dates are especially slippery — climb to the filing stamp when the date is load-bearing.

Share the timeline with a second reader before publish. Ask them to find the weakest row. If they cannot understand a row without your private lore, rewrite the row or add the missing exhibit.

From sheet to Evidence Board

On Gnosis, each strong row can become a pin with a date and credibility label. Premium’s board makes the map browsable; the free investigation should still narrate the spine dates. The timeline is the shared language between your working file and what the public sees.