lvl1 killer 
tim
ray-x
morph
zerox
violentJ
myself

those were just off the top of my head. I really just thought of who had the most medals in the lvl I could have missed someone, if so I am sorry

lvl2  killers
Tim
HP
Teflon
Suspect
Ray-x
CJ

lvl 3
GH
CJ
Tim
Suspect
Teflon
Ray-x