Charles Durning did not receive an Oscar nomination, despite winning NBR and being nominated for a Golden Globe, for portraying detective Moretti in Dog Day Afternoon.
We learn nothing about Moretti as a person. We don't know where he comes from we only know what it is that he is trying to do which is to keep the situation from escalating. This is a performance that is all about surface, this is not a criticism but rather the nature of the role. We never find out what Moretti really thinks about the situation we simply see that he is just going to do his best to reach a solution to it. Durning plays the negotiator in many ways, and is quite good in showing the methods of the negotiator. He plays Moretti in a variety of fashions, and effectively conveys the way that Moretti will try and get the hostages out.
The very time he talks to Sonny he is very firm and hostile as he tries to get him to immediately surrender, but after that clearly is not going to happen Moretti changes his tune considerably. Durning is excellent in establishing the way that the kind approach Moretti takes afterwards is just that an approach. It is not that Moretti is necessarily a nice guy, but rather the hostile approach clearly was not going to work so he has to change. Durning is very good in portraying how Moretti goes about talking to Sonny which is to keep him calm no matter what while trying to negotiate and push Sonny to release the hostages at the same time.
Durning makes Moretti both natural and artificial as he so gently speaks to Sonny. Although Durning makes Moretti genuine in that he genuinely wants to get the hostages out, but the artificiality comes in exactly how he speaks maybe too calmly and the way he always seems to be trying to make a certain eye contact and a physical closeness to Sonny. Durning gets across the way Moretti is just trying to play Sonny into seeing his way through almost a psychological conditioning as Moretti tries to seem like Sonny's best friend, even though he really is just trying to get the job done.
Durning is very effective throughout though and shows him realistically reacting to the situation and showing that Moretti can't keep up his method completely. He is very good in showing the frustrations he faces, and the believable reactions Moretti has throughout all the developments of the day. Durning is very compelling here in his own way creating an effective dynamic with Pacino and their back and forth throughout the day. It is a performance that adds a great deal to the whole of the film and makes the negotiation scenes properly come to life. Durning makes his own mark on the film despite this being such a limited role. His stamp is somewhat limited by the way his character exits with so little ceremony, but this a great example of an actor making something out of almost nothing.