Internal Investigation Scoping Framework 2026

Scoping Internal Investigations: A Decision Framework for Data Sources, Custodians, and Time Windows

Most internal investigations do not fail because of missing evidence. They fail because the scope was wrong from the start: too broad, too narrow, or poorly matched to where work actually happens in 2026.

Daily work now moves across Slack, Microsoft Teams, Google Workspace, Zoom, Jira, and Confluence. When an investigation opens, the evidence landscape has expanded well beyond email and shared drives, but scoping decisions often have not kept pace.

Getting scope right at the start determines whether evidence is defensible, whether collections are proportionate, and whether the investigation can close on time.

Why Scoping Has Become More Complex

Three structural shifts have made scoping significantly harder in recent years.

Collaboration data is now primary evidence. Work conversations that once took place over email now live in channels, threads, direct messages, and video meeting transcripts. As noted by Onna’s analysis of data collection for internal investigations, collaboration data includes not just messages but also edits, reactions, file attachments, calendar events, and system-generated logs. Limiting a collection to text alone means collecting an incomplete record.

Investigations routinely span multiple platforms. According to Cellebrite’s 2026 Industry Trends Report, investigations now routinely span devices, cloud platforms, and enterprise systems, with mobile data appearing in 66% of private sector cases and cloud data present in nearly half. A single matter may require collection from email, a messaging platform, a project management tool, and a cloud file repository, each with different retention policies, data structures, and export mechanisms.

Legal, HR, compliance, and IT teams often work from different assumptions. Without a shared scoping framework, teams may duplicate effort, miss custodians, or collect from the wrong time window, all of which create defensibility risks downstream.

A Decision Framework for Scoping Internal Investigations

Step 1: Define the Allegation Category First

Before selecting any data sources, map the allegation to the systems where relevant evidence is most likely to reside.

This mapping prevents over-collection and ensures proportionality, a standard increasingly evaluated in regulatory and litigation contexts.

Step 2: Build a Custodian List Using Organizational Context

Custodian identification is one of the most consequential decisions in any investigation. Missing a custodian at the outset can require reopening a collection later; over-designating custodians creates unnecessary data volume and review cost.

For a structured approach to custodian management in multi-app environments, consider three categories:

• Primary custodians: Individuals directly named in the allegation or with documented involvement

• Secondary custodians: Supervisors, approvers, or collaborators with likely visibility into relevant conduct

• Organizational custodians: Shared accounts, team channels, project workspaces, or distribution lists relevant to the matter

Organizational custodians are frequently missed in collaboration platforms. A Slack channel or Teams workspace may contain evidence that no individual custodian list would capture.

Step 3: Select Data Sources Based on How Work Actually Happens

Source selection should reflect where the relevant custodians do the work in question, not where investigations have historically collected from. Questions to ask:

• Which platforms did the custodians use for the work relevant to this matter?

• Are there platforms with short retention windows that require immediate preservation?

• Are project management tools (Jira, Asana, Confluence) part of the workflow?

• Were any communications likely to have occurred in recorded video meetings?

For guidance on scoping across modern collaboration platforms, the key principle is to follow the work, not the assumption. Defaulting to email when core communications occurred in Slack is one of the most common scoping errors in enterprise investigations today.

Step 4: Set a Defensible Time Window

Time window decisions carry legal weight. A window that is too narrow may miss relevant context; one that is too broad increases collection volume without proportionate value. Factors to consider:

• Allegation timeline: The date range when the conduct is alleged to have occurred

• Onboarding and offboarding dates: When did the custodian join and, if applicable, leave?

• Platform-specific retention limits: Some collaboration tools have default periods that affect what is recoverable

• Document hold trigger dates: If a legal hold was issued, the hold date may serve as a natural collection boundary

A useful starting point is three to six months before the earliest known date of relevant conduct, then expand based on what the initial collection reveals. Documenting the rationale for time window decisions is essential for defensibility.

Step 5: Validate and Narrow Before Collecting

Before executing any collection, validate the scope with the investigation team. This step is often skipped under time pressure, and it is the most common source of scope creep:

• Has legal hold been confirmed for each custodian and data source?

• Are the selected platforms capable of producing targeted, custodian-specific exports?

• Has IT confirmed the data exists within the defined time window?

• Are there data residency or cross-border transfer constraints?

A data collection platform that connects directly to collaboration tools and supports targeted, metadata-preserving collection will significantly reduce the risk of over-collection at this stage.

The Cost of Getting Scope Wrong

Under-scoping creates defensibility risk. Missing a custodian or a relevant platform, particularly if discovered in litigation, raises questions about investigation integrity. Over-scoping creates cost and timeline risk: broad collections drive up review costs, extend timelines, and can expose the organization to additional privilege and privacy considerations.

Both errors are increasingly avoidable. Real-time collaboration showed a 24% year-over-year increase as a primary driver for adopting SaaS-based investigative tools, with 80% of DFIR professionals agreeing that SaaS tools help them scale investigations as needed, according to Magnet Forensics’ 2026 State of Enterprise DFIR Report.

For organizations investigating workplace misconduct using collaboration data, a structured collection approach that preserves metadata, maintains conversational threading, and surfaces context alongside content is essential. Reviewers need to understand not just what was said, but when, by whom, and in response to what.

Internal investigations in 2026 require scoping decisions that match the complexity of how enterprise work happens, across multiple platforms, in collaborative workspaces, and with data structures that differ significantly from email. The teams that investigate effectively treat scope as a structured decision, not an informal starting assumption.

A rigorous framework for data sources, custodians, and time windows reduces investigation risk, supports defensibility, and makes collaboration data usable from the moment collection begins.

If your team is rethinking how it scopes and executes internal investigations across collaboration data, connect with Onna to see how a purpose-built data collection platform can give your legal, compliance, and information governance teams a faster, more defensible path from allegation to resolution.