Scott Cohen, who plays AIDS infected Eddie Reyna, in later seasons played Det. Harry Denby.
Simone says that eight years previously, his pigeons had all been killed by "Newcastle's". This fits the timeline in the real world, as well. Newcastle Disease spread from Europe to the rest of the northern hemisphere in the mid-to-late 1980s, and the carrier was racing pigeons
When HIV+ liar Eddie is shot and killed by his girlfriend when she learns he's infected her with the disease, Det. Adrienne Lesniak takes the gun out of her hands and puts it into her coat pocket. This was not an error in the show. The script explicitly wrote out that Det. Lesniak did this in order to contaminate the murder weapon and make it difficult or impossible to prosecute the shooter, because her actions were justifiable. And the script also has ADA Sylvia Costas say that it's likely the killer will get a suspended sentence in the end.