I am a little distracted by what I am watching. Here we have the protagonist from an Academy Award winner who portrays a bad ass (although a bit psycho one) in the film “The Hurt Locker” and here he is being a predatory, homosexual, predator, serial killer as the leading man in “Dahmer.” The actor in question is Jeremy Renner and I will say I am impressed. While I enjoyed his performance in THL I must say, seeing him portray JD is showing me something more, although both were characters with a good deal of mental instability (clearly). 
As for “Dahmer” the film itself is a bit all over the place. Directors like to use this device of jumping through time and blurring actual events with fantasies of characters far too often, in this case I will say it is acceptable. I can appreciate that the mind of someone who is not only capable of doing the things Dahmer did, but actually did it must be less than fluid in their thought patterns. Being disoriented by the film maker in order to force the typical viewer to relate is a worth tool in this instance, although others who use it for shock value make it seem cheap and gimmicky.
The movie progresses, although it does so in a rather hurkey jurkey type of motion. The idea of portraying the mind and actions of a serial killer would be, you would think, less than basic story telling. It makes for a good way to put the viewer in a state of uneasiness. Renner’s performance is convincing, although knowing even the basics about Dahmer he seems to be too attractive and far too well under control. However, I would think the only real way to portray a mentally ill person would be to have the same illness and to be able to perpetrate the actions of said mentally ill person. That would mean murdering 1 men and boys to make this particular serial-killer film (as did Jeffrey Dahmer) and well, that isn’t something that can really be done even in the name of art is it? At least not in a way that would be accepted by the industry and distributed in any real way.
Politics and art do not mix world, and if you are such a neanderthal that you believe otherwise you need to educate yourself.
As for the movie, it ends very anti-climactically almost as if they got tired of making the movie or couldn’t figure out the best way to end it… so they just stopped and threw up a full screen with some text on it.
Worth watching? Sure, if you have time and are drinking some cheap booze and want some brain food to give you some more reasons to look at most people with contempt and suspicion… 2 out of 5 for me.