Papers for

law enforcement analysts

Papers whose findings have a practical use for this group, as judged from the abstract. Open a paper to read what it means in practice.

Automated verbal lie detection has accuracy limits around 75 percent

A persistent accuracy ceiling in automated verbal deception detection

Abstract: Automated methods have been proposed to overcome the limitations of human verbal deception detection, but evidence remains fragmented across disciplines. We systematically reviewed 25 years of research (289 reports, 6,136 classification models) and meta-analyzed 3,653 models nested within 97 datasets. Pooled accuracy was 74.4% (95% CI: 71.2%-77.4%) with substantial heterogeneity. Accuracy was driven by methodological quality (ground truth, data source, class balance, evaluation procedure) more than by model complexity: the adoption of embeddings and large language models has not translated into improved predictive performance. Only 12.46% of reports used data with verifiable ground-truth, and only 23.96% of models were evaluated on independent data. The pooled accuracy aligns with meta-analyses of manual approaches, suggesting a ceiling of 70-75%, unlikely to be lifted by current research conventions.

Thu 8 OctComputation and Language
The gist
Detecting when someone is lying by analyzing their words has been a big challenge. The authors looked at 25 years of studies that tried to make computers better at spotting lies from what people say. They found that the best accuracy is about 74%, and this hasn’t really improved even with new machine learning technologies. Most studies didn’t use truly verified lie or truth labels, and often the tests weren’t done on completely separate data. This suggests that current approaches face a natural limit in how well they can detect deception from speech alone.
Open → 2610.12118v1

Anti-Semitism spikes on German social media after October attacks

The Surge of Anti-Semitism in German Social Media following the October 7 Attacks

Abstract: We investigate the extent to which the Hamas attacks on Israel of October 7, 2023, have affected German social media debates about Judaism and Israel. For this, we develop an approach to detect 26 anti-Semitic categories in user postings via large language models (LLMs). The approach is applied to Facebook and Telegram posts (N=125,718) from three months before and after the event. Methodically, we test different open-weight models in two setups---with and without user information as additional context to the post text. The best setup achieves up to 83 % F1-score for binary anti-Semitism detection on our manually coded validation set. User context provides valuable information for most LLMs and drastically reduces false positives, for example, when (critically) reporting on anti-Semitic incidents. Concerning our topic, we find that anti-Semitism is surging significantly on both platforms, while being about ten times more prevalent on Telegram compared to Facebook. Facebook users express anti-Semitic views most likely in posts about an alleged genocide in Gaza carried out by the Israeli army, whereas classic anti-Semitic stereotypes related to power and conspiracy theories are dominant on Telegram. After the attack, the discourse patterns on both platforms show signs of convergence, as classic anti-Semitism increases on Facebook, whereas Israel-related categories surge on Telegram.

Mon 28 SeptSocial and Information NetworksComputation and Language
The gist
After the Hamas attacks on Israel on October 7, 2023, anti-Semitic posts increased sharply on German social media sites Facebook and Telegram. The authors built a tool using large language models to detect 26 types of anti-Semitic content in over 125,000 posts from before and after the attacks. They found that Telegram had about ten times more anti-Semitic posts than Facebook, with each platform showing different common themes. The patterns of hate speech on the two platforms started to become more similar after the attack, with classic stereotypes rising on Facebook and Israel-related accusations growing on Telegram.
Open → 2609.36290v1

Pretrained speech models improved for noisy police radio audio

Pretrained ASR Pseudo-labeling for Noisy Police Audio

Abstract: Pretrained ASR systems perform poorly on noisy Broadcast Police Communication (BPC), hindering efforts to understand police decision-making. Pseudo-labeling offers an unsupervised path to improve ASR without expensive human labels, but the efficacy of this approach on very noisy domains is not known. In this work, we systematically assess the opportunities and limits of pseudo-labeling to adapt foundation ASR models (Whisper and Qwen3-ASR) to noisy BPC domain corpora from Baltimore and Chicago. We demonstrate that existing internal confidence metrics (log-probabilities and STAR scores) fail to distinguish between high and low quality BPC pseudo-labels, and we introduce an external LLM-as-a-judge filtering paradigm that leverages parametric knowledge to discard contextually implausible transcripts. Our LLM-judging filters more aggressively than internal metrics and significantly reduces WER of the pseudo-labeled training sets across the Baltimore and Chicago BPC corpora, though a substantial gap remains relative to an oracle filter. We also introduce a new cross-model pseudo-labeling paradigm where one model is finetuned with pseudo-labels from the other, and we identify this method as a promising direction for future pseudo-labeling work.

Thu 24 SeptArtificial Intelligence
The gist
Speech recognition systems struggle to understand noisy police radio recordings, making it hard to analyze police decisions. The authors studied a way to improve these systems without expensive human labels by using machine-generated transcripts (pseudo-labels). They found that usual confidence scores cannot reliably pick good transcripts from bad ones and introduced a new method using large language models to filter out unlikely sentences. They also tested using pseudo-labels from one model to train another, showing this approach could help future improvements.
Open → 2609.30469v1

Large language models struggle with criminal profiling before arrest

Before the Arrest: Benchmarking LLMs on Criminal Profiling from Incomplete Evidence

Abstract: Large Language Models (LLMs) are increasingly applied to legal and criminal justice tasks, yet existing work focuses almost exclusively on post-arrest scenarios where the suspect's identity is already known, leaving the critical pre-arrest challenge of inferring suspect characteristics from incomplete evidence largely unexplored. To fill this gap, we introduce the Profiling, Investigation, and Judgment (PIJ), comprising 2,500 real homicide cases from five countries. PIJ evaluates LLMs across three tasks that span the entire criminal investigation pipeline: criminal profiling, which requires abductive reasoning to infer suspect attributes from fragmentary scene evidence, crime process reconstruction, which tests structured information extraction, and sentence prediction, which demands legal deductive reasoning. We evaluate 9 powerful LLMs and find that performance degrades systematically as tasks shift from explicit fact extraction to implicit reasoning over unknown suspect profiles. Categories requiring inferential reasoning, such as motivation and victim-offender relationships, remain the primary bottlenecks. Further analysis reveals substantial gaps between LLMs and human experts, along with pervasive biases in gender, age, and motive attribution. Our findings indicate that pre-arrest inference from incomplete evidence remains an open challenge.

Thu 17 SeptComputation and LanguageComputers and Society
The gist
Figuring out who committed a crime before the suspect is caught is really hard, especially since the evidence is often incomplete. The researchers created a new dataset of real homicide cases from multiple countries to test how well large language models (LLMs) can guess details about suspects from limited evidence. They found that while LLMs can extract clear facts, they struggle with deeper reasoning tasks, like understanding motives or relationships between victims and offenders. The study also showed that these AI models still have big gaps compared to human experts and sometimes show biased judgments.
Open → 2609.19965v1