Kima's actions were, in fact, the epitome of betrayal.
Kima's actions were, in your opinion, the epitome of betrayal. The facts are that McNulty fabricated evidence, falsified documents and reallocated resources from other cases under false pretenses and Kima is reporting his actions to her commander. McNulty believed he was doing this in pursuit of the greater good - taking down Marlo. But we should critically examine that belief.
Who is to say taking down Marlo is the greater good? The budget cuts in the police department that resulted in Stansfield investigation being shutdown were not done out of malice or caprice. The school budget was at a deficit and cuts needed to be made to avoid teacher lay-offs at city schools.
In my opinion, McNulty wasn't seeking justice for the families of those 26 dead people in the vacants or even retribution against Marlo. He was frustrated that his own investigation was shut down and he wanted to prove he was smarter than the bosses.
The entire enterprise is going to fall down, anyway. Herc stole the phone number from Levy's office and i bet that phone number is protected by attorney - client privilege. As a result all the evidence gathered against Marlo's crew will be dismissed as fruit of a poisoned tree.