AI-Based Legal Information Retrieval Chatbot

This preprint presents an AI-based legal information retrieval chatbot designed to provide natural-language answers grounded in verified legal sources. The proposed system uses retrieval-augmented generation to retrieve relevant passages from a curated legal knowledge base containing statutes, regulations, and case summaries. A hybrid retrieval mechanism combines dense semantic retrieval with BM25 lexical retrieval, followed by grounded answer generation, atomic claim extraction, citation matching, and entailment verification. A confidence-based abstention mechanism prevents the system from returning unsupported legal claims when sufficient evidence is unavailable. The proposed evaluation considers answer accuracy, retrieval performance, citation correctness, and hallucination rate, with the objective of improving the reliability and traceability of conversational legal information access.