精简剧情：In1996agunmanopenedfirefromthetopofamultistorycarparkkillingpassersbyonWhitewaterHighStreet.SinceknownastheWhitewatermassacre,oneofthevictimswasatacticalsquadpoliceofficer,Sgt.NickPatterson,Supt.PeterBoyd’sbestfriend.Patterson’spolice-issuedGlockpistoldisappearedandwastheweaponusedtokillhim.TheGlockdisappearedthatdaybutisfoundsevenyearslaterbytwoboyssome10milesfromWhitewater.Boydandhisteamareassignedtosolvethemysteryofthevanishinggunastheconvictedsniper’ssolicitoriscallinghisclient’sconvictionintoquestion.Astheinvestigationcontinues,theteambegintodiscoveranomaliesthatmayinfactmeantheconvictedkiller,CarlMackenzie-whoalwaysmaintainedhisinnocence-mayhavebeenwronglyconvicted.