Custodian Interviews: Your First Line of Defense in Modern eDiscovery

If your company lands in litigation, chances are that valuable data won’t be sitting neatly in a single email server. It’s scattered across Slack threads, Teams chats, WhatsApp messages, cloud folders, or personal phones — “shadow IT” you never officially approved, or even heard of before. That is why custodian interviews — structured conversations with employees who control relevant data — remain important to a sound discovery strategy. They provide early insight, reduce costs, and help demonstrate good-faith efforts if preservation is later questioned.

Linked below is a recent article I co-authored with Rick Clark from CloudNine, which provides greater detail.

1. Go In With a Plan

Before you speak to anyone, it can be a good idea to map out:

• Who to interview: Start with employees who touched the dispute, plus anyone they point to next.
• What to cover: Craft a case-specific checklist — role, projects, devices, apps, personal accounts, deletion settings.
• Why it matters: Tell custodians the goal is preservation, not blame; that transparency protects both the company and them.

2. What You’ll Learn in a Good Interview

• Location of data, including unsanctioned “shadow IT” such as private Slack workspaces or personal Dropbox folders.
• Preservation measures, for example, suspending auto-deletion in an ephemeral-messaging app.
• What really matters so you can identify relevant data, negotiate a proportional discovery scope, and avoid the potential costs and inefficiencies that can come from over-collection.
• Context and terminology, such as project code names, acronyms, date ranges, key players, and practices/platforms that may have been in use during the relevant time period.
• Documented diligence; contemporaneous notes can show the company took reasonable steps to identify and preserve relevant ESI.

3. Coordinate Responsibilities

• In-house counsel: set policy, clarify corporate obligations, and reassure employees.
• Outside counsel: refine strategy and ensure legal defensibility.
• Service providers: supply forensically sound collection tools and comprehensive documentation.

Alignment among these groups can minimize gaps, both in the process and in the collection.

4. Build Trust, Get Better Answers

Explain the interview’s purpose, confirm that interviews are a routine legal requirement and are not accusatory, and emphasize cooperation. Clear communication fosters candor, which may prove valuable if additional data must be collected or depositions later proceed.

5. Ask About Modern Communication Channels

Consider asking specifically about:

• Chat platforms (Slack, Teams, WhatsApp, SMS/iMessage) and whether relevant messages are stored in private channels or direct messages
• Collaboration repositories (SharePoint, Confluence, Google Drive)
• AI tools (Copilot, Claude, ChatGPT)
• Personal devices or email accounts used for business
• Unsanctioned applications or cloud storage
• Visual aids or screen-share demos often jog memories

6. Coordinate With IT

It is often useful to consult IT personnel for a high-level view of standard data sources, retention policies, and system locations. Compare IT’s system-map and retention policies with what each custodian actually does; the cross-check helps surface local PSTs, USB drives, or other practice-policy gaps.

7. Apply Technology Carefully

Screen-sharing and real-time collection can:

• Confirm existence of specific documents and data sources during the interview.
• Preserve short-lived communications before they disappear.
• Reduce the interval between identification and preservation, lowering spoliation risk.

8. Maintain Detailed Records

Best practice is for your notes to capture:

• Custodian name, role, location
• Date, interviewer, format (Zoom, in person)
• Legal-hold acknowledgement
• All data sources and retention settings
• Preservation steps taken or required
• Follow-up tasks, owners, and deadlines
• Additional custodians or repositories identified

A living log helps demonstrate diligence and helps manage the project

9. Summary Recommendations

• Start early.
• Use a standardized interview form but tailor questions case-by-case.
• Keep the tone transparent and cooperative.
• Involve IT and cross-check what policies say versus real-world practice.
• Document interviews, tools used, and preservation efforts meticulously.

AI analytics is valuable, but talking to the humans who create the data continues to be a cost-effective way to control eDiscovery risk. Leading with thoughtful custodian interviews, backed by appropriate technology, can help build a defensible foundation.

Dig deeper: Our full article, Custodian Interviews: Critical to Defensible eDiscovery in the Age of Modern Communications, walks through interview checklists, role assignments, and documentation. Please also see our related Blog post from March 2025.

* Rick Clark, VP of Strategic Partnerships and Marketing at CloudNine, contributed to this Blog post.

© Arnold & Porter Kaye Scholer LLP 2025 All Rights Reserved. This Blog post is intended to be a general summary of the law and does not constitute legal advice. You should consult with counsel to determine applicable legal requirements in a specific fact situation.