Make LLMs See Like Investigators, Not Just Think More: The Role of Structured Analysis in Investigative Reasoning

Jaewook Lee, Myeong-Cheol Kang, Jong-hun Shin


Abstract
Criminal investigators and intelligence analysts have developed structured analytic techniques to evaluate competing hypotheses under incomplete information. This study examines whether such human expert investigative methodologies are also effective for narrative-based culprit inference in large language models (LLMs). Focusing on the task of analyzing evidence from complex narratives and identifying the perpetrator among suspects, we conducted experiments on 10 LLMs using the MuSR murder mystery benchmark. The PRISM framework, which applies investigative techniques, consistently outperformed existing general-purpose strategies across all models, with its effectiveness manifesting regardless of model scale. Ablation studies revealed that the hypothesis structuring stage is particularly crucial, accounting for 89% of the methodological improvement beyond information filtering. This suggests that domain-specific structures that specify “what to analyze” are more effective in LLM reasoning than simply increasing the number of reasoning paths.
Anthology ID:
2026.acl-long.1056
Volume:
Proceedings of the 64th Annual Meeting of the Association for Computational Linguistics (Volume 1: Long Papers)
Month:
July
Year:
2026
Address:
San Diego, California, United States
Editors:
Maria Liakata, Viviane P. Moreira, Jiajun Zhang, David Jurgens
Venue:
ACL
SIG:
Publisher:
Association for Computational Linguistics
Note:
Pages:
23037–23058
Language:
URL:
https://preview.aclanthology.org/ingest-acl/2026.acl-long.1056/
DOI:
Bibkey:
Cite (ACL):
Jaewook Lee, Myeong-Cheol Kang, and Jong-hun Shin. 2026. Make LLMs See Like Investigators, Not Just Think More: The Role of Structured Analysis in Investigative Reasoning. In Proceedings of the 64th Annual Meeting of the Association for Computational Linguistics (Volume 1: Long Papers), pages 23037–23058, San Diego, California, United States. Association for Computational Linguistics.
Cite (Informal):
Make LLMs See Like Investigators, Not Just Think More: The Role of Structured Analysis in Investigative Reasoning (Lee et al., ACL 2026)
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PDF:
https://preview.aclanthology.org/ingest-acl/2026.acl-long.1056.pdf
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