Music....
In addition to the odd "Over the Rainbow" theme that keeps playing, did anyone else catch whole patches of the orchestrations from "Kiss of Death"? "Kiss of Death" also starred Mature, which is odd.
If you get a chance to check it out, when Mature is in the apartment with the dead body, before her sister walks in, the music playing is the recurring theme of "Kiss of Death", particularly the music at the end of KOD.