Warner Bros. announced Tuesday it has officially signed Will Smith, Tom Hardy, Margot Robbie and Jared Leto to star in "Suicide Squad," a movie based on the DC Comics series, reports the Hollywood Reporter.

Model-turned-actress Cara Delevingne and Australian actor Jai Courtney are also cast to appear in the movie. While most of the castings have previously been announced, the studio has only now confirmed which characters the actors will play.

The movie's storyline centers on the "squad," a group of incarcerated supervillains who have opted to decrease their sentences by carrying out secret suicide missions for the good guys. If they survive the deadly missions, they reap the rewards.

Here is the squad character lineup: the Joker will be played by Jared Leto; Deadshot--known as a Batman villain--will be Will Smith; Harley Quinn, Joker's girlfriend, is played by Margot Robbie; Boomerang is Jai Courtney; Enchantress is Cara Delevingne, and Tom Hardy is the group's leader Rick Flagg.

Variety reports Warner Bros. is still hunting for an actor to play the role of Dr. Amanda Blake Waller, a former congressional aide and government agent placed in charge of the Suicide Squad. Nicknamed "the Wall," her character is without superpowers but she aids superheroes in the DC universe in other ways; often as a powerful antagonist.

Oprah Winfrey is rumored to be their first choice for the Amanda Waller role, according to Variety. For some, it may be a surprise to see the multimedia mogul listed for a film about killers and criminals. The former Oscar nominee has not commented on the proposition.

Viola Davis and Octavia Spencer have also been mentioned as possibilities for the role.

David Ayer, who wrote and directed the World War II action-drama film "Fury," will write and direct the film.

The DC Comics "Suicide Squad" supervillains first appeared in 1959.

 The film is expected to start shooting in April with a release date of Aug. 5, 2016.