Her voice weak from a recent stroke, Tanya Moore lists three goals, in this order: Bury her daughter. Get stronger. Find out who killed the 21-year-old, leaving her on a Fairfax road, her skull crushed.

“All I want is answers so that I can have some closure on what happened to my child because I don’t know,” Moore, 41, said Sunday. “Somebody knows. But I don’t know.”

Fairfax police found Shelinda Arrington lying unconscious in the 7100 block of Harrison Lane, just a few blocks from where she lived with her mother, at about 11:30 a.m. Friday. Police believe Arrington got out of her car, began arguing with another driver and was run over.

On Sunday, police said no arrests had been made in the death and that detectives continue to look for a dark-colored sport utility vehicle with temporary tags. Once they locate it, detectives hope to determine whether Arrington knew the other driver or whether it was a case of road rage.

The Office of the Chief Medical Examiner has ruled that the cause of death was a crush injury.

Moore says she can’t imagine why her daughter, who was set to graduate from ITT Tech in November, would have gotten out of the car.

“She did not like confrontation at all,” Moore said, adding that Arrington was an honor roll student and volunteered with her at the Lions Club.

In ninth grade, Moore says, Arrington adopted the goal of becoming a criminologist, and after graduating from West Potomac High School in 2009, she left to study at a college in Richmond. The only reason Arrington returned home a year later, Moore said, was to help take care of her because she suffers from sickle cell anemia.

“I wanted her to get her education, but she wanted to put me first,” Moore said. “She said, ‘Mommy, it’s hard to concentrate knowing you’re home sick, in and out of the hospital.’ ”

On April 30, Moore suffered a stroke, and Arrington visited her daily at Virginia Hospital Center. That’s why Moore grew worried when Friday morning came and went and Arrington hadn’t arrived.

Moore hopes someone contacts detectives with new details. Police ask anyone with information about the incident to call 703-691-2131. In the meantime, Moore says she is trying her hardest to get well so that she can help police find answers.

“I’m dealing with it the best I know how,” she says. “She was my world, and I was her world. She was my best friend, and I was her best friend. It’s been like that since she came out of my womb.”