It's one thing to walk into a 'Halloween' or 'Friday the 13th' movie and know what's coming your way. The guys in the masks carrying big blades are clearly the ones you should be running from. But what happens when someone doesn't have "killer written all over their forehead?" See, those are the ones that you have to watch out for, the ones with the ability to pose as nice, normal people, but then do a complete 180 once they've worked their way into your home and life.

The premise of the upcoming film 'The Roommate' is really quite clever. A college campus is an opportune location for a silent threat to take advantage of a new student's vulnerability. In honor of Rebecca (Leighton Meester) preying on her random roommate, Sara (Minka Kelly), in theaters this weekend, we're taking a look at some of the other deadly characters who used the sneak attack approach to get the one up on their victims.

They're lethal, murderous and at time psychopathic, but when you first meet these folks, they're as harmless and friendly as they come.
Saw
R2004
Based on 32 critics

A doctor (Cary Elwes) must kill his cellmate or his family will die. Read More

The Stepfather
R1987
In Theaters on January 23rd, 1987

A teen (Jill Schoelen) distrusts her mother's (Shelley Hack) smiling new husband (Terry O'Quinn). Read More

Hard Candy
R2005
Based on 30 critics

A 14-year-old girl (Ellen Page) looks to punish a suspected pedophile (Patrick Wilson). Read More

Funny Games
R2008
Based on 33 critics

Two deranged young men take a vacationing family hostage and subject them to torture. Read More

The Lovely Bones
PG-132009
Based on 36 critics

A young murder victim watches over her family -- and her killer -- from heaven. Read More

Orphan
R2009
Based on 25 critics

A woman suspects that her recently adopted daughter is behind a series of strange occurrences. Read More

The Roommate
PG-132011
In Theaters on February 4th, 2011

An unstable college student (Leighton Meester) becomes dangerously obsessed with her roommate. Read More

Psycho
R1960
In Theaters on June 16th, 1960

A woman (Janet Leigh) stops at a motel run by mad Norman Bates (Anthony Perkins). Read More

categories Features, Cinematical