In 1989, Beverly Hills brothers Lyle and Erik Menendez brutally gunned down their wealthy parents. Did they do it for the money? Or was a dark history of mental and sexual abuse to blame?

"What makes people behave the way they do?" asked Edie Falco, the veteran actress who plays the Menedez brothers' defense attorney, Leslie Abramson.

The Sopranos and Nurse Jackie star actually got her start on the original Law and Order.

Falco said, "Any New York actor has a history with Law and Order. It's sort of a rite of passage that we all kid about. If you haven't done a Law and Order you're either new to town or you're just really terrible."

Coincidentally, she was often cast in the show as an attorney.

"And all these years later," Falco said, "working with a lot of the same people."

This take on the Menendez story goes well beyond the tabloid headlines, and into the hearts of the accused.

"It feels a little intrusive, in a way, what we're doing," she admitted.

The production is taking place close to the real-life story's actual locations.

"We're shooting it in L.A. This is where they lived," said Gus Halper, who plays Erik Menendez in the series. "Some certain scenes we're shooting where they actually took place, and we're saying the things they actually said. It's just very surreal sometimes."

The writers have tried to clarify the brothers' motives, shedding new light on reports of abuse by the parents.

"You never can excuse murder," Falco said, "but it makes a difference knowing what they'd been through."

There's no doubt that Lyle and Erik committed the crime that put them away for life, with no chance for parole. The only question is: Why?

Falco said, "Things are really not always as they appear."