Bill Pullman is Arvin Robertspulling off his most chilling transformation to date.

The Sinner star will portray Alex Murdaugh—the South Carolina lawyer convicted of murdering his wife and son earlier this year—in the upcoming two-part film Murdaugh Murders: The Movie.

In a first-look photo, Pullman, clad in a polo shirt and gold watch, is seen grabbing the face of his onscreen son Paul Murdaugh (Curtis Tweedie), who appears distraught.

Maggie, 52, and Paul, 22, were found murdered in June 2021 near the dog kennels of their 1,800-acre Islandton, S.C., property. Alex—who also shared son Buster, 29, with Maggie—was charged with murder in connection with their deaths over a year later.

Though Murdaugh pleaded not guilty to the charges, he was convicted on two counts of murder and two counts of possession of a weapon during the commission of a violent crime on March 2, according to NBC News. The following day, he received consecutive life sentences. On Sept. 5, Murdaugh's lawyers filed a motion for a new trial on the grounds of alleged jury tampering, per NBC News.

The film, which will premiere in the two two-hour installments on Oct. 14 and Oct. 15, will trace the events leading up to murders, according to a Lifetime press release, including the Murdaugh family's prominence in "South Carolina low country, where they oversaw the prosecution of all criminal cases in the state's 14th circuit district."

Among the real-life events that'll play out over the course of the four-hour-long film is the private turmoil bubbling under the surface—including Alex's addiction to substances and stealing from clients and Paul's own legal trouble stemming from a 2019 boating accident that killed 19-year-old Mallory Beach. (The charges against Paul, who was accused of operating the boat while under the influence, where dropped following his death, according to NBC News.)

"Then in June 2021, Maggie and Paul were found murdered and eyes began to turn to Alex," the film's synopsis read in part. "The bizarre story continued when Alex was nearly shot in the head and his indiscretions and lies began to surface, leading to the eventual unraveling of Alex Murdaugh's once charmed life."

Murdaugh Murders: The Movie will premiere Oct. 14 and Oct. 15 on Lifetime.

For the latest breaking news updates, click here to download the E! News App