Video-Based Interrogation - Best Practice Example | Mangold

Video-Based Interrogation - Legally Compliant, Efficient, and Practical

A statewide project in Hesse demonstrates what modern audiovisual interviewing can look like today: legally compliant, efficient, and practical - based on Mangold’s mobile and stationary AV interview systems.

Why Audiovisual Interviewing Is Becoming More Important

Police interviews have faced new challenges in recent years. Stricter legal requirements, increasing demands for transparent procedures, and the growing importance of objective evidence mean that traditional written protocols are reaching their limits.

Written interview records are time-consuming, capture nonverbal cues only inadequately, and inevitably contain subjective elements. As a result, multiple interviews are often required - creating extra workload for the police and placing additional strain on witnesses, victims, and suspects, especially those who are particularly vulnerable.

Audiovisual interview systems offer clear advantages: they document the entire course of the interview, enable objective review, and provide a reliable basis for investigators and the judiciary.

Overview of the Project in Hesse

The Witness Protection Act of 1998 first enabled video-recorded testimony. With the introduction of Section 136 (4) of the German Code of Criminal Procedure (StPO) in 2020, the use of video-recorded suspect interviews was significantly expanded. Hesse took up these legal developments early and implemented a statewide concept for audiovisual interviewing.

At the heart of this modernization are Mangold’s mobile and stationary interview systems, developed and integrated in close cooperation with the Hessian State Criminal Police Office and rolled out across the state.

The aim of the project was to capture interviews exactly as they occur - complete with video, audio, and the behavior of all parties involved - while improving the protection of witnesses, victims, and suspects. Today, the systems are available in police stations throughout Hesse and are used daily in investigations.

Mobile and Stationary Interview Systems by Mangold

Hesse uses a combination of mobile suitcase systems and fixed installations. This ensures the right setup for every situation.

Mobile Suitcase Systems

The mobile systems are housed in a robust transport case and can be set up within minutes. They are ideal for:

• Satellite or temporary offices without a permanent interview room
• Ad-hoc interviews in flexible locations
• Special situations, such as psychiatric facilities or correctional institutions

The mobile design makes it possible to conduct audiovisual interviews practically anywhere - without the need for extensive infrastructure.

Stationary Systems

Stationary systems are used in dedicated interview rooms, often equipped with separate control rooms, monitoring screens, intercom (“Voice-of-God”) solutions, and live transmission capabilities.

In cases involving children or other sensitive situations, this technology provides significant benefits: victims can be interviewed in a protected environment without having to face suspects. Live video transmission and indirect questioning reduce emotional stress and improve statement quality.

Technology in Use: VideoSyncPro

At the core of the system is VideoSyncPro, software that synchronously records video and audio while meeting all legal requirements for admissible, courtroom-ready documentation.

Key Features of VideoSyncPro

• Synchronized audio and video recording
• Encrypted data storage
• Time markers and pausing during interviews
• Automated report generation for post-processing
• Detailed user and permissions management to protect sensitive content
• Chat server for communication between interview officers
• Offline AI transcription directly on the system - no external servers or internet required
• The AI-powered transcription converts statements into written text, significantly reducing manual workload - while ensuring full data protection, as all processing happens locally on the system.

“Setup is quick and straightforward, and operation is intuitive. Even under difficult conditions, we can reliably record legally compliant statements.” Police Chief Inspector Scholz, Hessian State Criminal Police Office

Implementation, Training, and Statewide Deployment

The rollout in Hesse was carried out in close coordination between the Hessian State Criminal Police Office and Mangold International. In addition to technical integration, particular emphasis was placed on training and user acceptance.

A train-the-trainer concept ensured structured knowledge transfer throughout the organization and enabled smooth statewide implementation. The new workflows were aligned with existing processes from the start.

Today, more than 50 Mangold systems are in use across Hesse - both mobile suitcase systems and stationary solutions in dedicated interview rooms.

More Objectivity, Less Effort

Feedback from the field is overwhelmingly positive:

• Improved objectivity and traceability of interviews
• Fewer repeated interviews, especially in sensitive cases
• Noticeable reduction in workload thanks to more efficient documentation
• Higher acceptance in court due to unalterable AV recordings

Audiovisual interviewing is not an end in itself - it is a tool that benefits everyone involved: investigators, interviewees, vulnerable persons, and ultimately the justice system.

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