Cybercrime research is still in its infancy. Although an increasing number of scholars from various disciplinary backgrounds are involved in cybercrime studies, many of the “big questions” remain unanswered. A major problem is that it is simply difficult to study the criminals committing cybercrimes: criminals try to hide their illegal activities and are usually not disposed to talking openly to researchers, which limits the usefulness of the more traditional social sciences’ research methods. Furthermore, the innovative methods used in cybercrime research come with their own limitations: although they usually provide big datasets with sometimes hundreds of thousands of data points, they only provide superficial data or, in the case of scraped data, only contain information about one very small step in the crime scrips of cybercriminals. Police investigations, therefore, provide unique knowledge about criminal networks and their members due to the wide use of intrusive investigative methods such as wiretaps and IP taps, observations, undercover policing, and house searches. This chapter describes the pros and cons of using police investigations to shed light on cybercrimes.