Improving investigations into online sexual abuse of children

A mother discovers that a man has contacted her daughter in a chat and asked her to take a photograph of herself and send it to him. The mother takes a screenshot of the message and reports it to the police, who begin investigating the case.

The police identify a man who has contacted not just one child, but thousands of children in different cities, regions and countries. His computer contains many gigabytes of images and videos of children. He has shared the files with others, who have in turn shared them further, spreading them around the world.

This is a typical scenario involving what is known as internet-related sexual abuse of children. It is an umbrella term covering several types of criminal offences, including the exploitation of children through sexual posing, the purchase of sexual acts involving children, child pornography offences and contacting children for sexual purposes, also known as grooming.

“This is a type of crime that is increasing and is very challenging for the police to investigate, as investigations require many different kinds of expertise. Someone with specialist knowledge in one area will not necessarily have expertise in another, which makes collaboration essential,” says Oscar Rantatalo, Professor at the Unit for Police Work.

We want to help make small changes that can have a significant impact.

Investigating these crimes involves many different challenges. They often cross regional and national borders. Investigators need advanced technical expertise, the ability to examine abusive material and experience of leading and working in large investigative teams, sometimes remotely. The work can also be emotionally demanding because it involves vulnerable children, and specialist skills are needed both to interview children and to communicate with their families.

In recent years, artificial intelligence (AI) has also become increasingly significant, both in the development of these crimes and as a tool in criminal investigations.

Oscar Rantatalo has a broad background and a wide range of research interests.

ImageAlekzandra Granath

Since 2023, Oscar Rantatalo has led the research project Cross-functional teamwork in criminal investigation: An intervention project aimed to support collaborative work for detectives.

The project focuses on professionals working with cases involving internet-related sexual abuse of children.

“We have studied how effective collaboration can be promoted. How can investigators work better together? How can we facilitate collaboration between, for example, prosecutors and digital forensics specialists, so that they understand one another, speak the same language and can conduct investigations effectively? How can people work remotely on investigations of this kind? And how can we ensure a good working environment for those carrying out these mentally demanding tasks?”

“We want to help make small changes that can have a significant impact.”

Striving for more efficient investigations

The aim of the research is to help society investigate and prosecute these crimes more effectively. Time is particularly important when children are involved.

“Our research can support those working on the front line. These crimes are very distressing.”

Our research can support those working on the front line. These crimes are very distressing.

In early June, Oscar Rantatalo was awarded just over SEK 1 million in research funding from Forte to extend the research project and work on putting its findings into practice within the Swedish Police Authority.

“It feels really good. Unfortunately, this is a type of crime that is continuing to increase, according to both national and international statistics. AI is also playing an increasingly important role in these crimes.”

Earlier this year Oscar Rantatalo was awarded just over SEK 1 million in research funding from Forte to extend the research project. “It feels really good. Unfortunately, this is a type of crime that is continuing to increase."

ImageAlekzandra Granath

Although online sexual abuse of children is the focus of Oscar Rantatalo’s current research, his research interests more broadly concern organisational structures within the Swedish Police Authority. Among other things, he has studied how the police handle critical incidents, the major reorganisation of the Swedish Police Authority in 2015, criminal investigations in rural areas and police education.

I’m interested in many different areas.

His academic background is broad. He was trained in education and has worked in psychology, business administration, education and police education.

“I’m interested in many different areas, which also makes it difficult to sum up my research in just a few words. For example, I also find police education interesting to study, and that is a very different field from research on the sexual abuse of children,” he says.

First Professor of police science

Oscar Rantatalo is now Umeå University’s first professor of police science at the Unit for Police Work.

Police science is a relatively young academic field in Sweden. In 2025, Umeå University became the first university in the country to admit a doctoral student in police science.

“The Swedish Police Authority is Sweden’s largest government agency. It is a very practice-oriented and tradition-bound organisation and is not accustomed to making extensive use of research. At the same time, there is an international trend among police organisations towards working in a more evidence-based way, which is creating a demand for research,” says Oscar Rantatalo.

Why is research on police work important?

“The work of the Swedish Police Authority is fundamental to society. That makes it important to study policing from several perspectives. We need critical perspectives that can help us understand and theorise social control and social order. But we also need practice-oriented research conducted in collaboration with the police, looking at what works and what does not, so that resources can be used effectively.”

Gives me greater opportunities to create a path for others who want to pursue research in this field.

Umeå University’s new professorship in police science gives Oscar Rantatalo greater opportunities to contribute to the development of police work and to research addressing the challenges facing the Swedish Police Authority.

“It also gives me greater opportunities to create a path for others who want to pursue research in this field,” says Oscar Rantatalo.

Investigations require a wide range of expertise

Cross-border collaboration: Digital crimes often cross both regional and national borders. This means that the police need to collaborate not only across police regions but also with police authorities and judicial systems in other countries.

Technical expertise: Specialist technical expertise is needed to handle and investigate digital evidence, which may involve encryption and complex technical systems. In recent years, the use of AI has increased rapidly in this area, both in the production of abusive material and as a tool in investigations.

Investigative experience: Investigations of this kind can quickly become very extensive. Experience and expertise are therefore needed to lead and coordinate large teams, often with people working remotely.

Working environment: Reviewing and investigating material involving vulnerable children can be emotionally demanding. In some cases, abusive material may be interspersed with depictions of animal cruelty or other forms of violence, making it difficult for investigators to prepare themselves for what they may encounter. The work may also lead to secondary trauma, where repeated exposure to the suffering of others affects the investigator personally.

Interviewing children: Specialist expertise is needed when interviewing children, who may experience feelings of guilt and shame. Expertise is also needed when communicating with parents and other family members.

Oscar Rantatalo Professor

+46 90 786 65 64