Cassie is a single woman who thinks like a man and lacks the sensitivity of a woman. Her hard heartedness creates a barrier between herself and the opposite sex. There is a reversal of roles between Cassie and her partner Sam Kennedy (Ben Chaplin). After Cassie and Sam have sex Cassie kicks him out of the bed rather abruptly. Sam is hurt. He wants to stay and is interested in a relationship with Cassie.

"Murder by Numbers" begins with the discovery of a woman found murdered in the woods and the circumstances surrounding the murder are the focus of the plot.

The movie centers around the relationship between the wise guy popular kid Richard Haywood (Ryan Gosling) and the brainy yet disturbed friend Justin Pendleton (Michael Pitt). The two become fascinated with the concept of murder and kill a woman picked at random. They place her body in the woods making it look like the action of a serial killer by brutalizing the body and cutting off the one finger. They set the police on the trail of a janitor at the school well known for selling drugs to the students. Justin murders the janitor making it look like a suicide and the case is dismissed.

Cassie is determined to prove that the two teenagers were responsible for the murders. She is haunted by her own victimization and on a quest to nail the wise guy Richard.

Scenes flash to Cassie as she lay stabbed by an ex-husband. She reveals to Sam that years ago she was the unpopular high school kid that fell for the cute star athlete. Her ex-husband stabbed her seventeen times and we see the physical and emotional scars it has left.

The film is suspense combined with drama. It keeps us guessing until the end which one of the teens is really responsible for the murder. Although, we are left routing for the shy disturbed Justin over the slick Richard.

"Murder by Numbers" is not that memorable as a suspense film. There are no quotable lines and the acting is mediocre. But the story succeeds at depicting teenage life and it actually brings you back to high school. Cassie is forever changed by her high school experience. She says to the suspects in five years nobody will really care who was popular and who wasn't.

Although this is true, you never really forget which group you fit into. It stays with you. During "Murder by Numbers" I found myself thinking back to my own high school experience at the same time wanting justice for the heinous crime committed. Considering what goes on in high schools today such as the Columbine incident the storyline is realistic and it makes you think.