How to Perform a Departing Employee Investigation

What is a departing employee investigation and why it matters

A departing employee investigation is a focused, defensible review of the employee’s devices, accounts, and access to determine if company data was misused, exfiltrated, or destroyed. In plain language: we confirm what they took, when, how, and whether it violates policy or law—then package those facts for court or negotiation. The process must balance speed, proportionality, and privacy while preserving admissible evidence under a proper legal hold.

• Key risk: Spoliation and loss of crucial logs within days—undermining TROs, preliminary injunctions, or trade secret claims.
• When it arises: Last weeks before notice, during notice period, and immediately after separation—especially where the employee had access to source code, sales pipelines, pricing, or R&D.
• Immediate action: Issue a targeted legal hold, preserve devices and cloud logs, and halt automated wipes or account deprovisioning until collections are complete.

At a glance: fast risks and quick wins

• Fast risk: Short retention windows for Microsoft 365, Google Workspace, Slack, and endpoint logs. Why it matters: Waiting even a week can erase audit trails needed to prove misappropriation.
• Fast risk: BYOD phones with corporate email or apps. Why it matters: Without consented, scoped collection, critical messages and attachments may be lost.
• Quick win: Suspend device reimaging and MDM wipes; forensically image the workstation first. Why it matters: Imaging captures deleted files, USB history, and cloud sync artifacts.
• Quick win: Export mailbox and audit logs in native formats early. Why it matters: Preserves timeline evidence for declarations and meet-and-confer leverage.
• Quick win: Narrow scope to business-critical repositories. Why it matters: Supports proportionality and controls budget.

For broader support across matters, see our digital forensics services and eDiscovery services. If mobile data is in play, our mobile device forensics team can help.

Counsel playbook: a defensible workflow

Use this streamlined workflow to preserve options, control cost, and produce admissible results.

• Step 1: Preserve endpoints. Instruct IT to secure the laptop/desktop and prevent reimaging, wiping, or reassignment; suspend auto-deletion policies. Why it matters: Protects chain of custody and prevents spoliation arguments.
• Step 2: Scope a targeted vs. full collection. Prioritize systems tied to alleged misappropriation (e.g., workstation, OneDrive, Teams/Slack, CRM). Why it matters: Supports proportionality while capturing the most probative sources.
• Step 3: Request specific natives/logs your experts need. Ask for mailbox exports (PST/EML), M365 Unified Audit Log, OneDrive access logs, device event logs, USB history, and cloud sync records. Why it matters: Native evidence retains timestamps and metadata necessary for reliable timelines.
• Step 4: Validate and document. Maintain chain-of-custody forms, hash values for images/exports, and collection notes; cross-check multiple sources. Why it matters: Ensures admissibility and withstands Daubert or foundation challenges.
• Step 5: Report to claims. Provide a timeline mapping actions to claims (CFAA, DTSA, breach of duty), highlighting key exhibits and potential remedial requests. Why it matters: Converts technical artifacts into persuasive facts for TROs or settlement.

Reconstructing a Defensible Timeline from Endpoint and Microsoft 365 Logs in plain English

A defensible timeline ties together what happened and when across the laptop, email, cloud storage, and collaboration apps. In simple terms, we align system events (like file copies or USB insertions) with account activity (like OneDrive syncs or email forwards) to show the story with timestamps.

Why it matters: Courts and opponents look for corroboration. A clean, cross-validated timeline supports TROs, narrows discovery, and pressures early resolution. Weak or piecemeal evidence invites proportionality objections and erodes credibility.

• Step 1: Pull native M365 audit logs and mailbox exports, plus endpoint artifacts (USB history, recent files, cloud sync records). Why it matters: Native logs preserve metadata needed to align events reliably.
• Step 2: Rule out benign explanations by comparing access patterns to normal workflows and scheduled IT tasks. Why it matters: Reduces false positives and enhances admissibility.
• Step 3: Produce a synchronized timeline in UTC with screenshots or CSV excerpts as exhibits. Why it matters: Clear, time-normalized exhibits aid declarations and meet-and-confer negotiations.

Example: The workstation shows a USB inserted at 7:14 p.m.; within two minutes, 1,200 files from “Client Proposals” were accessed. M365 logs record concurrent OneDrive sync failures, followed by three emails to a personal Gmail with zipped attachments. Taken together, these corroborated events support a narrowly tailored TRO and immediate return order.

Common mistakes to avoid

• Over-collecting or under-collecting: Boiling the ocean drives cost without adding probative value; collecting too little sacrifices key artifacts. Calibrate scope to disputed repositories and relevant period to meet proportionality.
• No cross-check: Relying on a single source (e.g., email only) weakens the narrative. Corroborate with endpoint, cloud, and messaging data to bolster admissibility and reduce alternate explanations.
• Poor documentation: Missing chain-of-custody, hash verification, or collection notes invites foundation challenges and sanctions risk; document every handoff and process step.
• Delayed log exports: Waiting on audit log pulls leads to expiration or rotation. Export early; retention windows are often days to weeks by default.
• Self-help imaging: Well-meaning IT actions can alter metadata. Use certified forensic methods or retain a neutral expert to avoid spoliation.

Practical applications for case strategy

Use forensics to sharpen your litigation posture and control the discovery narrative.

• Request natives and logs early: Specify PST/EML, M365 Unified Audit Log CSV, OneDrive/SharePoint audit exports, and system event logs in initial preservation letters and RFPs.
• Frame exhibits for the court: Present a concise timeline with 3–5 anchor events and linked exhibits; translate artifacts into plain-English captions (who, what, when, how).
• Budget and schedule signals: Start with a targeted assessment (workstation + M365) before expanding to mobiles or third-party apps; set a two-week initial window to inform TRO or PI strategy.
• Meet-and-confer posture: Offer narrowly tailored collections and neutral keyword testing to reduce burden while insisting on native logs to maintain fidelity.
• Remedial relief: If exfiltration is shown, seek return/deletion certifications, neutral forensic remediation, and cost-shifting for preservation failures.

For more practitioner tips and case studies, explore our blog alongside our core digital forensics offerings.

FAQs

• How fast should we act after notice?: Within 24–48 hours. Issue a legal hold, secure devices, and export audit logs. Ask IT to pause wipes and reassignments immediately.
• What if the employee used personal devices?: Implement a BYOD protocol with consented, scoped collection limited to business data. Validate with cross-source logs to avoid overreach.
• Do we need a full forensic image every time?: Not always. Begin targeted (key devices/accounts) and expand if indicators arise. Maintain proportionality while preserving essential artifacts.
• When should we involve an expert?: Early—before IT wipes or deprovisions accounts. An expert preserves native evidence, sets scope, and prepares courtroom-ready timelines.

Next steps

A well-run departing employee digital forensics investigation protects trade secrets, supports eDiscovery obligations, and sets up early, favorable outcomes.

• Checklist: preserve endpoints and logs; collect targeted sources; validate and corroborate; report with a clear, defensible timeline.
• Legal value: reduce sanctions risk, strengthen TRO/PI filings, and drive efficient, proportional discovery.

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