Ok guys. i have a couple questions because I missed some parts of the show tonite.
First, who were those two Puerto Rican guys and what cannection did they have to the drugs?
Second, how did the detectve discove that Debbie was the murderer?
This part of the plot was kinda murky, so I may not have it exactly right.
The Puerto Ricans were the real owners of the cocaine that had been hidden in the sofa. They mentioned something about this dive of an apartment was paid up in cash for months in advance. The guy who owned the sofa was killed (they didn't say by who), and then Debbie & boyfriend found it hidden in the sofa when they went to re-cover it. It was implied that the Puerto Ricans were watching the apartment and followed Debbie & boyfriend.
Because Sonny told Jimmy that the Puerto Ricans were heavily armed (at the abandoned cargo site), Jim later wondered why they left him there and didn't kill him. The answer: they only wanted the coke; they weren't murderers. So, then if they weren't murderers but only wanted the coke, why did they kill Debbie's boyfriend, and why wasn't he shot? Since the boyfriend was killed with a baseball bat, Jim deduced that it was someone besides the Puerto Ricans who killed him, and that led them to Debbie as the most likely suspect.