My issue is that there is a bit "too much" acting; people who have been involved in cases like these, be it up close or just a reporter, tend to speak about them in a detached, matter-of-fact way. This is both natural and helpful, and is probably a kind of defense-measure on part of the human psyche. The officers, forensic investigators, family and so on are often here showing the "theatre" syndrome, exaggerating both voices and body language.
Maybe I'm just boring, analytical and interested in details, but don't forget - every good police officer or forensic detective probably are as well :-P
If you don't care or saw the movie and didn't notice anything unnatural, then good for you - you got your moneys worth :)
For a comparison in what I mean, take a look at *any* episode of *any* true crime investigation, e.g. Crime Investigation Australia.