The Origami Killer

Okay, I got this idea that's been rolling in my head for the past few days, and I want to ask you guys what you think of it. Best part is, it may have enough action in it and good enough characters that I may actually keep it.

Its called How to Save a Life, and it revolves around a series of homicidal murders that have taken place throughout Chicago. The killer leaves no evidence of the murder, no finger prints, no stray hairs, no traces of DNA, except the simple origami piece left at the scene of the crime. Known as The Origami Killer, he's on the FBI's most wanted list, but for the past year he's evaded every investigation that the FBI, CIA, Police Force, and Federal Government have put through...often resulting in the death of the investigators, a single origami piece the only evidence turned up on the sense of murder.

Mars Alexander was a former FBI agent living a successful and happy life on the edges of the Chicago suburbs with his wife, Miranda, and two Twin boys, Mathew and Joshua. However, when a gang hit-and-run attack results in the death of his 8-year old son, Joshua, Mars' life is turned upside down. Now divorced and having left the FBI, he lives with his other son, Matt, who he had become increasingly distant to. However, when Matt is captured by the Origami Killer, Mars pushes everything he has aside and re-joins the FBI in the hopes of saving the only thing left in his life to love.
Throughout the story, he meets up with two companions: Chloe, a private investigator who is constantly fearful of when the Origami Killer with ultimately kill her, and Logan, a 19-year-old gang member hunting down the Killer after a deal gone sour ends with the death of most of his crew, yet he also *spoilers* happens to be one of those who killed Mars' first son, Joshua.

So, what do you think? suggestions (what withe the origami ect) would be much appreciated

-dev