Jack & Jill by James Patterson (1997, Paperback, Reprint)

Great book.as James Patterson is a great writer of horror novels.

The book begins at night, with a man calling himself Sam Harrison, wearing a disguise and stalking United States Senator Daniel Fitzpatrick. Sam plans on killing the senator, and has been planning this for quite some time. The Senator has just gone into a bar with a young woman. Sam is very sharply dressed, to blend in the bar. After a few minutes he strolls into the bar and waits. Soon he goes upstairs to the Senator's flat. The young woman answers the door. "Jack" she says. "Jill" he replies back.

In another part of Washington DC, another killer was hiding in a "tent" among an area of thick pines. He is also putting on a disguise, but his is like a homeless person. He walks toward a poor neighborhood and blows up a balloon and waits for a kid to show up. A little six year old black girl approaches him. As he goes to give her the balloon he takes out a baseball bat that he was hiding behind his back and starts swinging at her.