For 90 minutes, authorities say, Brittany Norwood sat in her victim’s parked car, concocting a plan to cover up the horrendous crime scene she had just created in the yoga apparel store where they worked.

Her colleague, Jayna Murray, lay dead, bludgeoned and stabbed inside Bethesda’s Lululemon Athletica shop, prosecutors said. Something was tied around Murray’s neck. There was blood everywhere.

The plan that Norwood formed — as detailed in court Monday by Montgomery County’s top prosecutor — involved planted evidence, phony injuries and a pathological series of hundreds of fabrications.

“Her cunning and her ability to lie is almost unparalleled,” John McCarthy told District Court Judge Gary Everngam, saying that Norwood, 28, should be held without bail until she is tried.

McCarthy said the attack in the store occurred after closing March 11, shortly after Murray reported to a manager that she had discovered stolen store merchandise inside Norwood’s bag. Norwood bludgeoned Murray for as long as 20 minutes and struck so many blows in the same places on her body that it was difficult to determine the exact number of wounds, the prosecutor said.

“The nature of this crime is shocking in terms of the level of violence,” McCarthy told the judge. “The majority of the blows were directed at [Murray’s] head. Her skull was crushed during the attack.”

Everngam agreed to hold Norwood without bond. No trial date had been set.

Making her first court appearance, Norwood was shown through a video feed from the jail. She said her name and answered yes when Everngam asked whether she had read the charges against her. For 15 minutes, she stood expressionless, her arms folded across a stand positioned in front of her.

A review of public records available online in Norwood’s previous places of residence on Monday turned up no criminal past. McCarthy said he was unaware of one. Friends of the suspect said that descriptions of such a violent attack stunned them.

But law enforcement officials said they had heard from past acquaintances of Norwood’s who said she had a reputation as a thief. Two friends from Stony Brook University, where Norwood studied sociology and played soccer, said the same thing in interviews.

“She was my best friend in college. We had a falling-out because the girl was like a klepto,” said Leanna Yust, a former soccer teammate of Norwood’s.

Yust said that Norwood stole money and a designer shirt from her.

Both classmates said Norwood also could be fun to hang out with. “She could be so sweet, so funny. Amazing soccer player,” Yust said.

Norwood attended the university’s College of Arts and Science from 2000 to 2004 but did not receive a degree, a school spokeswoman said.

She previously worked at the Willard InterContinental Hotel and a Lululemon Athletica store in the District, said sources with knowledge of the case who spoke on the condition of anonymity because the investigation is ongoing. Norwood had recently transferred to the Bethesda Lululemon store, the sources said.

On March 11, Murray checked Norwood’s bag and found merchandise that appeared to have been stolen from the store, authorities said.

Murray and Norwood left the store at 9:45 p.m., police said. About six minutes later, Murray called a manager and told her about the bag check, McCarthy said in court. A short time later, Norwood called Murray, said she had left her wallet in the store and that she needed Murray to let her back in.

The women reentered the store at 10:05 p.m. At 10:30 p.m., employees at the adjacent Apple store heard two women yelling at each other, authorities said. It was unclear what Norwood is alleged to have used to attack Murray, but police have said that Norwood stabbed and beat her co-worker. Some of Murray’s wounds went from one side of her neck to the other, McCarthy said. Her spinal cord was severed.

Norwood left the store to move Murray’s car, which might have been parked illegally because Murray thought the return trip to the store would be brief.

Norwood drove the car three blocks to a lot adjacent to a farmers market. There, she was “sitting in the car for an hour and a half trying to decide what to do,” McCarthy said.

Norwood’s conclusion: Walk back to Lululemon to create the illusion that two masked men had entered the store and attacked the women, authorities said.

According to authorities, Norwood cut a hole in Murray’s pants to make it look like the woman had been sexually assaulted. She created shoe prints by donning men’s shoes from inside the store — size 14 — and walking through the blood, police said. She inflicted injuries on herself, grabbed zip ties from the store and bound her feet and hands, using her teeth to tighten the ties, McCarthy said.

The next morning, when police came to the store, Norwood was there — tied up and in a bathroom — and proceeded to tell her tale.

McCarthy said that Murray’s and Norwood’s blood were found inside Murray’s car.

Norwood was represented during the bond hearing by Alan Drew, a lawyer from the county public defender’s office. He declined to comment after the hearing.

Some of Norwood’s relatives went to Montgomery police headquarters Friday when authorities said that the woman’s story had fallen apart. Detectives let at least one of the family members talk to the suspect alone.

McCarthy said Norwood was asked why she fought with Murray.

“I don’t know,” Norwood said.

Staff researcher Julie Tate contributed to this report.