The organic emission mix is what differentiates us as individuals. Every person while alive has a distinct odor, whether one wants to admit it or not. Upon death the body will release a mix of esters and other hydrocarbons, along with some sulphur compounds, that reflects what your body was composed of at the time of death. While there may be a generalized "smell of death", sensitive measurements using calibrated equipment could identify individuals once the organic emission mechanism after death is better understood. This is chemistry. Chemistry is fascinating. A gas chromatograph can tell you exactly what compounds, and in what amounts, a corpse is emitting, after capturing the gases and firing up the GC.