This movie was definitely not what I expected to see. I did not see any trailers for this movie or read any reviews. I just went assuming it was about the Zodiac serial killer.

The movie starts off well with a scene of the first murder mixed in with lightly humorous moments and dialogue. However, the movie takes a turn down an investigative lane that only people with interest in this particular case would love and the rest would just fall asleep.

As for the acting, I can not say much for Jake Gyllenhaal or Robert Downey Jr. because they play roles that I feel wasn't much of a challenge -- they play themselves, especially Downey Jr. in the role of a cracked out alcoholic. But, I was impressed with Mark Ruffalo, as this is easily one of his better performances.

The bottom line is: If you're looking to be entertained with a murder mystery with thrills and suspense... watch something else. This movie is something that (sorry to borrow the phrase) "Only a mother could love." As in the writer of the book.