Deep Research in Westlaw and CoCounsel: Building Agents That Research Like Lawyers
Westlaw's existing AI-Assisted Research using LLMs produced helpful narrative summaries from cases, statutes, and regulations, but these were only a starting point; attorneys still had to manually dive deeper to gather authority, surface edge cases, and resolve nuanced legal questions that require iterative multi-step investigation.
How it works
Common implementation structure
How this type of workflow is generally built, generalized across documented cases — not tied to any one vendor's stack. Click any stage to read what happens there. Specific products that implement these stages appear in “Tools commonly seen” below.
Stage 1 · Initial legal question submitted
The workflow begins with an initial legal research question from which the system plans multi-step strategies.
Tools used
Claude 4KeyCiteWestlawCoCounsel
Outcome
Deep Research is now live in Westlaw Advantage and CoCounsel, providing agentic legal research that plans, executes in parallel, validates citations, and produces verified reports — with comprehensive analyses completing in about 10 minutes.
What failed first
Traditional RAG-based systems could produce a surface-level answer but could not handle multi-step legal reasoning — they answered the question without assessing the strength of the inference, jurisdictional variation, or competing arguments.