WATCH: Lululemon, Apple store video released

Surveillance footage of Brittany Norwood's interview with police.

ABC7 has obtained video of convicted killer Brittany Norwood lying to police about what happened inside Lululemon the day she killed Jayna Murray at the upscale yoga shop in Bethesda.

Surveillance video, released Monday, also shows what Apple employees did and didn't do when they heard the struggles next door.

"Do you know how many times they hit me, no how many times did they hit you? I don't know, I just don't remember. I just started doing what they said."

The video shows Norwood talking to police one week to the day after she brutally killed her co-worker Murray. It is her third interview with detectives James Drewery and Dmitri Ruvin and she continues to claim Murray was murdered by two men who burst into the store.

“He cut my stomach and my chest first and I was trying to fight him,” Norowood says in the video. “And he hit me in the head.”

The case unravels

“She was very believable at times when appropriate she cried and her hands were shaking,” says Ruvin. “She was very believable.”

See raw footage of the interview.

But by that Friday, Ruvin knew Norwood was lying. As one detective says, they were just trying to give her more rope.

“Of course obviously everyone denies at first,” Ruvin says. “But we were hoping she would confess.”

But it would be one detail she "remembered" a week after the incident that would be a pivotal turn in the investigation.

"Prior to him sexually assaulting me and zip tying me, they made me move her car, I know where her car is."

This, investigators say, is where her web of lies began to unravel.

For the first time, video from the Apple store next to Lululemon is also being made public.

During the murder trial, it provoked a public outcry because it shows Apple store employees listening to the brutal assault on Murray and even her dying pleas for help. Those employees did not call police. One thought it was just woman's drama.

State's attorney John McCarthy points out they broke no laws.

“In fairness, could they have known what was going on on the other side of the wall,” McCarthy says. “In fairness no.”