After almost six months, more than a hundred interviews and a couple of dozen dead-end tips, Redmond police are no closer to catching a killer now than they were in the weeks after Victoria Mardis was shot as she stopped to retrieve papers she accidentally had left on the roof of her car.

Police don't believe the 49-year-old Seattle nurse was targeted, nor do they believe anyone close to her was involved in her death last July, said Officer Stacey Holland. No witnesses have come forward, and a surveillance tape obtained from a nearby gas station provided no clues, Holland said.

"One of the theories we've been working from the beginning is that it was a random killing and that's why it's been so difficult for us," Holland said.

Mardis was killed by a single gunshot to her right cheek around 11 p.m. July 26 in the 8100 block of Willows Road in Redmond. She was shot after parking her car at the Willows Ridge Apartments complex to retrieve patient files she had left on the roof of her car as she was leaving work.

A passing motorist called police when she saw Mardis' body on the sidewalk, less than a quarter-mile from where Mardis worked as a home-health-care nurse for Apria Healthcare.

The company recently donated $5,000 in reward money for information in Mardis' slaying, adding to the $1,000 reward Crimestoppers already had offered.

"There isn't a day that goes by when we don't see her name on a patient file or somebody mentions her," said Monica Medalia, Apria's Redmond branch manager. "Most of our employees drive by the site of her murder on a daily basis, and we see her picture on Crimestoppers posters throughout Redmond. There are so many constant reminders.

"She was such a great lady, and it's so sad she left the world on those terms."

The slaying was Redmond's 10th homicide in the past 25 years and the department's only unsolved killing in recent history, Holland said. Police are discounting no theories and are still looking into the possibility that Mardis was the victim of a "thrill kill" or gang violence, she said.

One detective is working full time on the case with a second detective helping out part time, Holland said. So far, Redmond police have interviewed more than 100 people and received about 25 tips on the department's tip line.

"We have so little to go on, and that's made this case difficult and frustrating for the investigators," Holland said. "We're looking at everything, and we're quite sure there's someone out there with information.

"She was somebody's mother, somebody's wife, so we have to keep trudging on and hope something will break."

Anyone with information about the slaying is asked to call the tip line at 425-556-2581 or Crimestoppers at 1-800-CRIME-13.