Keira Knightley has filed a harassment complaint with the New York Police Department against Landon Rust, the 29-year-old who disrupted Knightley's play "Thérèse Raquin" on opening night last Thursday, Oct. 1.

The actress filed the complaint specifically after Rust yelled "We're going to be in heaven together," reported Page Six.

"She was scared. She wanted to document the incident to start a paper trail in case this guy turns into a stalker," a law-enforcement source told the publication. "If he starts following her around and showing up where she is, then she can get an order of protection against him, but only with a paper trail," the source added.

Last week, the actress was forced to stop her performance at Studio 54, minutes into the play when Rust stood up in his seat and started to approach the stage where he threw a bouquet of roses at her feet, reported the Daily Mail. Following the incident, Rust was escorted out of the theatre in handcuffs and was issued a summons for disorderly conduct.

Knightley, a true professional, did not break character once during the disturbance. The play was eventually shut down for a short intermission following the interaction.

"I would say Keira did a very good job of keeping her composure. The guy kept yelling things and she kept going on with the play without missing a beat," an eye witness told E! News. "This was all professionalism. I respect it."