The Watcher

"The Watcher" is basically an exciting horror film. Keanu Reeves
plays a serial killer who strangles young women with piano wire.
He chases a homicide detective to Chicago for reasons unclear
at the beginning of the film (this part is revealed later). Since
Reeves thinks of his murders as a game, he sends pictures of his
next intended victim to the detective. Apparently, he doesn't
think that the cop can find the intended victim in time to save
her life (and for most of the movie, Reeves is right).
Meanwhile, a subplot involves the homicide detective and his psychotherapist
(Marisa Tomei), whom he seems to have a bit of a crush on. As
you might get, Reeves eventually targets her as a means of getting
back at his old cop friend.
"The Watcher" is a good murder mystery, and it certainly is an
interesting role for Reeves (I don't think he's ever played a
serial killer before). I thought the plot was well- woven, although
a little predictable.
Rated R for violence and language