Usage of Unmanned Aerial Vehicles (UAVs), which are more colloquially known as drones, has seen an exponential rise, with malicious use being of significant concern. This has recently led to considerable research efforts on their detection, using different sensor technologies, such as lidar, radar and camera among others. In order to address the detection problem, in this work we study lidar based detection of intruding drones with the purpose of improving the state of the art on the subject.