Theft apparently led to the death of 30-year-old Jayna Murray inside a Lululemon Athletica store in Bethesda, Md., Pat Collins reported.
Brittany Norwood, the 28-year-old coworker accused of killing Murray, appeared in court Monday afternoon. Norwood is charged with murder.
Montgomery County State's Attorney John McCarthy said Norwood grabbed a weapon or tool of some sort inside the store and attacked Murray, leaving her with wounds that were "too numerous to count." Her skull was crushed, there was a ligature around her neck and her spinal cord was severed, Collins reported.
Montgomery County police said that Norwood inflicted superficial wounds on herself and then tied up her arms and legs after committing the crime.
The March 11 slaying shook the upscale Bethesda shopping district, where violent crime is rare.
Apparently, Murray looked in Norwood's bag before they left the store that night and found items she believed belonged to the store, prosecutors said. Murray called the manager, who decided to deal with it the next day. Murray and Norwood then left the store and locked up. Afterward, Norwood called Murray back to the store.
Investigators said that workers in the adjacent Apple store had heard the sound of an argument between two women March 11. Norwood had originally told police that two masked men had sexually assaulted her and Murray in the store, and then killed her coworker.
Detectives said that after several interviews, inconsistencies developed in Norwood's story, which was contradicted by physical evidence at the scene.
"Her cunning and her ability to lie is almost unparalleled," McCarthy said
Murray's car was found in a lot behind the Montgomery Farm Women's Co-Op in Bethesda. Inside, investigators found her blood and Murray's blood, Collins reported.
Authorities said that a medical examination in the hospital revealed no evidence of sexual assault. In addition, bloody footprints found at the scene were traced to a set of shoes used by the athletic store to fit pants, and another pair of shoes belonging to Norwood.
Detectives also recorded a conversation Norwood had with her family, Collins reported.
"I'm sorry. I don't want to disappoint you," Norwood said. "I don't want to talk about her because they may be recording this.
"Why did you fight with her?" her brother asked.
She replied, "I don't know."
Norwood appeared in court Monday via video conference from the local jail, where she was ordered held without bond. Her public defender declined comment.
Norwood is a native of Washington state. She was a talented soccer player at Stony Brook University in New York. She had been sued by her landlord in Columbia Heights over unpaid rent, but she has not been involved in any other previous legal trouble.
The Lululemon shop remained locked Monday morning, with strips of yellow police tape still attached to the door and its windows covered from view by large pieces of brown paper. Businesses along the street displayed white ribbons in Murray's memory.
Fan, Follow and Text: Get the latest from NBCWashington.com anytime, anywhere. Follow us on Twitter and Facebook. Sign up for our e-mail newsletters and get breaking news delivered right to your mobile phone -- just text DCBREAKING to 622339 to sign up. (Message and data rates may apply.)