Cat and Mouse by James Patterson

Just as Alex Cross is beginning to feel that life is good and he is finally coming out of the depression he’s been in since the death of his wife, he is called to Union Station train terminal – a man is on the loose, firing at random into the swarming crowds of travellers. Psychopath Gary Soneji seems determined to go down in a blaze of glory, and he wants Alex Cross to be there. Will this be the final showdown?