Investigating Trafficking in Human Beings. An Investigation Protocol for Law Enforcement in the Baltic Sea Region

This document is a practical guidance developed to support law enforcement authorities in strengthening criminal investigations into trafficking in human beings (THB). Produced by the Council of the Baltic Sea States (CBSS), Task Force against Trafficking in Human Beings, and funded by the Government Offices of Sweden, the Protocol responds to a clear operational need across the Baltic Sea Region and Ukraine.   

Purpose and focus 

While victim identification has improved in recent years, investigations often stall at the crucial next stage. Prosecutions and convictions for human trafficking remain low, not due to a lack of victims, but due to challenges in moving from identification to a structured, evidence-based investigation. 

This Protocol is designed to address that gap. It offers guidance on what investigators should consider, prioritise, and do after a potential human trafficking situation has been identified, with the aim of improving investigative quality, strengthening cases for court, and disrupting trafficking networks. 

What the Protocol offers 

The publication combines legal clarity with operational practice. It introduces the specific characteristics of human trafficking as a crime and explains why it requires investigative approaches that differ from other serious offences. Practical guidance is provided on, among other things: 

• Correctly classifying and initiating trafficking investigations 

• Applying a consistent victim-centred perspective 

• Using intelligence, surveillance, digital evidence, and financial data effectively 

• Understanding trafficker-modus, control mechanisms, and criminal structures 

• Identifying high-risk environments for sexual and labour exploitation 

• Working proactively and across borders, including cooperation with Europol 

Real case examples and practitioner insights illustrate how investigations can be built in a way that clearly demonstrates exploitation and withstands judicial scrutiny. 

Intended audience 

The Protocol is intended both as an introduction and a practical tool for: 

• Police cadets and investigators new to trafficking cases 

• Experienced investigators seeking structured guidance and updated practices 

• Prosecutors, strategic leads, and police trainers developing national or regional training 

It can be used in daily investigative work as well as in education, training, and capacity-building contexts. 

 Contributors 

The Protocol was developed with substantial contributions from practitioners and experts representing: 

• Europol

• South Jutland Police, Denmark 

• Prosecutor General’s Office, Lithuania 

• National Police Competence Group on THB at Kripos, Norway 

• Border Guards Headquarters, Poland 

• National Police Headquarters, Poland 

• Police Authority, Sweden 

• Frontex 

Their combined operational experience ensures that the guidance reflects real investigative challenges faced by law enforcement agencies across the region. 

Overall aim 

By providing clear, practical, and up-to-date guidance, this Investigation Protocol seeks to support law enforcement authorities in moving beyond identification – towards stronger investigations, more effective prosecutions, and better protection for victims of trafficking. 

If you would like to receive the Investigation Protocol in digital form, please fill in the form below.

Please note that the Protocol is not intended for publication on public websites.

The Investigation Protocol is also made available and disseminated by Europol to participating states and Europol operational partners, via the Secure Information Exchange Network Application (SIENA).