audio has surfaced of michael slager , 33 , laughing and admitting to experiencing a rush of adrenaline in the minutes following the shooting .
walter scott , 50 , was shot five times in the back as he ran away from the traffic stop on april 5 .
slager has been charged with murder after cell phone footage of the incident emerged which contadicted the initial police report .
the audio of slager talking with a senior officer at the scene was picked up the damcam in his vehicle which had been recording the initial incident .