Why 'Law & Order True Crime: The Menendez Murders' Was a 'Shocking' Experience for the Cast (Exclusive Video)

"All that stuff just kind of came up in the research of it and that was shocking and upsetting," Gus Halper, who plays Erik Menendez in the new NBC series, told TooFab at PaleyFest in Los Angeles earlier this month.

The miniseries explores the infamous court case that dominated the media in the '90s after Erik and and Lyle Menendez (played by Miles Gaston Villanueva) shot their wealthy parents with shotguns, purchased just says before the murders, inside of their family's Beverly Hills mansion. Jose Menendez (Carlos Gomez), a successful Cuban-American business executive, was shot in the center of his head, while his wife, Mary "Kitty" Menendez, was shot more than 15 times, including once in the face, which left the socialite unrecognizable.

Halper told TooFab he was particularly surprised to learn about the details of the Menendez parents' alleged child abuse, which defense attorneys argued played a huge role in the boys' crime.

"It's an upsetting answer, but the details of the abuse, the extent of the abuse, the psychological affects that this type of abuse can have on a kid and how common it actually is," Halper said.

Villanueva said getting into character on some days during the shoot was actually "really scary."

"When you're actually trying to internalize it and capture it on the day, it's a really, really scary thing to try and tap into," he told TooFab. "The most difficult and shocking thing is when you're, you know, holding the shotgun or reloading them or going up to mom or whatever it is. It's just that sort of adrenaline and that mindset that you try and get an ounce of that can be really overwhelming and scary. Playing them has been such a shocking, challenging thing."

Edie Falco ("Nurse Jackie," "The Sopranos") plays the brothers' defense attorney Leslie Abramson. Although the actress was not able to meet the woman in real life, she was able to get a sense of her personality by watching on-camera appearances.

"There's plenty of footage on Leslie Abramson," Falco told TooFab. "There's videos of the trial and video of her on a talk show and her speaking to reporters. There's tons of stuff to look at and she wrote a book. She didn't like her hair. She hated it. From what I understand, it was a constant source of angst for her, but I thought it was pretty cool personally."

Gomez, on the other hand, had to make a lot of assumptions about Mr. Menendez, since the only evidence of his character lies in what was written about him in the media at the time.

"I was surprised that first of all, he was an immigrant. He came to this country at 16 from Cuba, put himself through college, he worked for RCA, he worked for Hertz, he worked for a company called Carroll Co at the time -- that was an entertainment [company] that worked on the 'Rambo' franchise -- and again he amounted a $14 million empire in 1990, which is a lot of money for an immigrant that came to this country," Gomez told TooFab.

"If none of this would have happened, he would have become a hero for a lot of hispanics, and unfortunately a lot of these allegations came up, and now he's just remembered as a sexual offender of his children, who murdered both him and his wife, so it's tough way to go," Gomez said. "It's tough for his family who have to live with that legacy and we don't know. There's only four people who know what happened. The two kids and the two parents, who are 6 feet under, so we'll never find out."