Classifying Crime Types using Judgment Documents from Social Media

TL;DR

This paper introduces a novel NLP-based approach for classifying crime types from judgment documents, addressing data imbalance with a new preprocessing module and leveraging pretraining on large datasets to improve accuracy.

Contribution

The study presents a Crime Fact Data Preprocessing Module (CFDPM) and an improved BERT model with dynamic masking, enhancing crime classification accuracy on social science texts.

Findings

Achieved state-of-the-art results on benchmark datasets.

Validated effectiveness of CFDPM in balancing data distribution.

Demonstrated improved generalization with pretraining and fine-tuning.

Abstract

The task of determining crime types based on criminal behavior facts has become a very important and meaningful task in social science. But the problem facing the field now is that the data samples themselves are unevenly distributed, due to the nature of the crime itself. At the same time, data sets in the judicial field are less publicly available, and it is not practical to produce large data sets for direct training. This article proposes a new training model to solve this problem through NLP processing methods. We first propose a Crime Fact Data Preprocessing Module (CFDPM), which can balance the defects of uneven data set distribution by generating new samples. Then we use a large open source dataset (CAIL-big) as our pretraining dataset and a small dataset collected by ourselves for Fine-tuning, giving it good generalization ability to unfamiliar small datasets. At the same time, we use the improved Bert model with dynamic masking to improve the model. Experiments show that the proposed method achieves state-of-the-art results on the present dataset. At the same time, the effectiveness of module CFDPM is proved by experiments. This article provides a valuable methodology contribution for classifying social science texts such as criminal behaviors. Extensive experiments on public benchmarks show that the proposed method achieves new state-of-the-art results.