Who is Edward Deege from L.a. Requiem and what is their importance?

Edward Deege is the vagrant, who witnesses the killer approach Karen Garcia in a car identical to that belonging to Joe Pike. He also claims to have seen a man who very closely resembles Joe Pike behind the wheel of that car. The killer tracks him down and kills him, a crime that Harvey Krantz later attempts to pin on Joe Pike while he is incarcerated for the murder of Eugene Dersh.