Christchurch's mosque shooter flew a drone over Masjid Al Noor weeks before his attack.
Police confirmed the Australian gunman used an aerial recording device “in the vicinity of the Deans Avenue mosque ” on January 8, 2019.
https://www.stuff.co.nz/national/christchurch-shooting/122232602/christchurch-mosque-terrorist-used-drone-over-mosque-before-march-15-attack