Can AirDrop be traced by police?

Could you elaborate on the potential for law enforcement agencies to trace AirDrop transactions? Given the nature of AirDrop as a wireless file sharing feature, does it leave behind any digital footprints that could be utilized for forensic analysis? Are there any specific measures users can take to ensure their privacy when utilizing AirDrop for file sharing? Furthermore, how does the encryption implemented in AirDrop factor into its traceability? And finally, have there been any notable cases where AirDrop has been used in illegal activities and subsequently traced by the police?