Abstract:
Legal intelligence aims to analyze texts within the legal domain automatically by employing various natural language processing (NLP) technologies. This field has garnered significant attention from the NLP community. One of the most critical tasks in legal intelligence is Legal Judgment Prediction (LJP). This task seeks to forecast judgment outcomes, such as applicable law articles, charges, and penalties, based on the fact descriptions of legal cases, making it a promising application of artificial intelligence (AI) techniques. However, current LJP methods primarily address cases with a single defendant, neglecting the complexities of cases involving multiple defendants. In real-world criminal cases, multiple defendants are often involved, creating intricate interactions that single-defendant LJP technologies cannot accurately handle. These existing technologies struggle to distinguish judgment outcomes for different defendants in such scenarios. To advance research in LJP tasks involving multiple defendants, this paper presents a large-scale multi-defendant LJP dataset with three key characteristics: 1) It is the largest manually annotated dataset for multi-defendant LJP; 2) It necessitates distinguishing legal judgment predictions for each defendant; 3) It includes comprehensive judgment chains, covering criminal relationships, sentencing contexts, law articles, charges, and penalties. Furthermore, this paper conducts an extensive and detailed analysis of the dataset, examining the distribution of law articles, charges, penalties, criminal relationships, sentencing contexts, text length, and number of defendants. It also provides statistical insights into multi-defendant judgment results and the chain of judgment based outcomes. Additionally, this paper introduces a novel chain of judgment based method, featuring a strategy for generating judgment chains related to the crime facts and a comparison strategy to differentiate correct judgment chains from easily confused ones, enhancing overall effectiveness. Experimental results reveal that the multi-defendant LJP dataset presents a significant challenge to existing LJP methods and pre-trained models. However, the chain of judgment based LJP method significantly surpasses baseline methods, highlighting the crucial role of judgment chains in improving LJP.