Bodie was 16 at the time, and at the point of the series he was never above being the #2 for a crew. And assuming since all the known muscle of the Stanfield Organization weren’t teenagers, I would believe that Wallace was his first kill.

As for Partlow’s “ethics”, his saying a hitter’s first shouldn’t be someone he knows, I firmly believe that he says this only considering the success of the hit. For some, the more you know the person, the harder it is for the person to be a target. Thus, I think Chris was just making sure the job got done and nothing else.

And for Wallace, that hit was a justified hit, because Wallace was going to snitch. In a day or less, the police was going to take him to the Grand Jury and that’d be it. Sure, he decided to go back to work, but as a mindful and aware boss, Stringer Bell did what he had to do to protect the organization (or rather himself).