When Katie Featherston was a child, her mother filmed everything she did. Years later, Oren Peli followed her around with a camera for seven grueling days as she improvised a script in which a demon haunted, possessed and killed her. Out of that week came the recent unexpected hit “Paranormal Activity.”

Featherston was a shy girl growing up in Arlington, Texas. In junior high she took a drama class and fell in love with the theatre. She knew instantly that she wanted to be an actress.

She came to SMU for the strong theater program reputation. She took classes in movement, voice and acting. She played Babe in “Crimes of the Heart” in the Greer Garson Theater, and Lainie in a student production of “Two Rooms” in the Owen Fine Arts Center’s basement. Although she doesn’t consider herself a singer, she took part in her class’s production of “Assassins,” a musical known for its difficult vocal arrangements.

In 2005, Featherston graduated from SMU and moved to Los Angeles. Within a few months, she found an audition notice through the online resource LA Casting. When she got there, Peli asked her, “Why do you think your house is haunted?” The question caught her off guard, but she went with it, and after a number of callbacks, got the part.

Under Peli’s direction, Featherston and co-star Micah Sloat worked 18-hour days filming “Paranormal Activity.” It was a collaborative process; instead of working off a script, the actors improvised under Peli’s guidance. Whole storylines were generated and discarded. Together, the three produced a horror film whose eerie impact lingers long after the final credits.

Finally, after a period of viral guerilla advertising, Paramount Pictures released “Paranormal Activity” across the country. It quickly became a hit. The weekend before Halloween, it grossed $22 million, which propelled it to the top of the box office charts and made it the horror flick of the season.

Since then, Featherston has been flooded by offers. She’s met with casting directors and producers. Strangers and bartenders recognize her. Although she hasn’t committed to anything, she’s reading scripts and deciding what to do next.

Featherston feels “incredibly blessed” for her time at SMU and gushes about how thankful she is for all the opportunities she’s had. To SMU students she said, “Enjoy every single second.”