New 'anxiety-inducing' horror movie that sets a serial killer in a concert is based on a bizarre true story

Arguably, some of the best horror movies to date have drawn inspiration from true events.

The likes of The Conjuring, A Nightmare on Elm Street, Annabelle were all inspired by people's real life experiences, while movies such as The Silence of the Lambs and Pyscho were loosely based on the same notorious serial killer, Ed Gein.

With the success of these horror movies in mind, director M. Night Shyamalan followed suit and looked to real-life events for ideas for his his newest film, Trap.

Starring Josh Hartnett as the lead, Trap follows a serial killer (Hartnett) evading a police blockade while attending a concert with his daughter (Ariel Donoghue).

While Hartnett's character of Cooper Adams is fictional, Shyamlan is said to have drawn inspiration from a police sting operation for the movie.

Named Operation Flagship, the sting was conducted by the United States Marshals Service and the Metropolitan Police Department in Washington DC in December 1985.

Approximately 3,000 wanted people were sent invites and were told they had won complimentary tickets to the Redskins-Bengals game and were invited to a pre-game brunch at the Washington Convention Center.

The American football team were hugely popular at the time and demands for that game in particular were extremely high.

Operation Flagship took place in December 1985. (Bernie Boston/Contributor/Getty)

The invites were sent to the last known addresses of the wanted criminals and of the 3,000 sent, 167 responded.

The officers involved with the sting operation are said to have trained for six weeks and officials went as far as brining in deputy marshals from outside of DC to ensure that some of the fugitives didn't recognize local law enforcement officers.

Once the criminals arrived at Washington Convention Center, officers posing as Flagship International employees checked their IDs and they were later broken into smaller groups so that the arrests could be made.

In total, 101 criminals were arrested as a result of the operation.

Speaking about Operation Flagship to Empire, film director Shayamalan said: "It was hilarious. The cops were literally cheerleaders and mascots. These guys were dancing as they came in. And they were all caught. It was so twisted and funny."

Josh Hartnett stars as Cooper Adams in Trap. (Warner Bros.)

Critics' reviews started trickling in ahead of Trap's release, and they're seemingly good so far.

One person labelled Hartnett's performance as 'anxiety inducing from beginning to end', while someone else said of the actor: "Watching Hartnett flip between goofy, embarrassing father figure and concerned serial killer is a real treat."

Someone else described Trap as 'another deliciously complicated addition to a filmography that simply refuses to fit into any neat and tidy boxes'.

Trap hits US cinemas today, 2 August.