Despite it happening on 1 April, between 06:00 and 07:00, investigating officers say it is no laughing matter.
Anyone who saw or can identify the runner is asked to contact PC 62 Flatres by calling 725111 or by emailing Jordan.flatres@guernsey.pnn.police.uk.
Alternatively, people can contact CrimeStoppers anonymously on 0800 555 111.