Investigate \"Missing\" (Watch_Dogs)

Sometimes you go walking in the night,will find the corpse and get scared.Some sounds near the corpse terrible,like the voice.

anyone had this problem: after completing the mission , we kill the leader of a gang (the bald one and only tattoo) I have does not appear to be the main task they are simply not on the map , only DOPA is , what to do , maybe someone knows?