SPOKANE, Wash. -

Spokane Police are on the hunt for a killer who stabbed a 55-year-old woman to death early Thursday morning as she walked her dog along the Spokane River near South Riverton Avenue and Magnolia.

The attack happened just after 8:00 a.m. on a trail along the south bank of the river. Witnesses say they first saw 55-year-old Sharlotte Mcgill walking and yelling for help. They say she made it about 20 yards before collapsing to the ground.

"I kept hearing someone yell 'help me, help me' and I thought it was a dream," neighbor Janelle Shippy said.

Neighbors like Shippy rushed to McGill to help until paramedics arrived. McGill underwent emergency surgery for stab wounds to the head, chest and arms but died at the hospital.

"There was nothing I could do and there was nothing she could do," Shippy said.

Friends of McGill say she worked at the Spokane Valley Costco in member services. The store says McGill has worked for Costco for 12 years and had recently transferred to the Valley location from Wenatchee.

Interim Spokane Police Chief Scott Stephens said the department is using every available resource to find the attacker. K9 units are in the area, as are additional officers from different segments of the department. Stephens urges people to use caution and if they see something suspicious, don't approach the area - call police or Crime Check at 456-2233.

"It's a tragic case and that is why it is so troubling for the community, because it appears that an innocent person is walking their dog and then brutally attacked," Stephens said.

Stephens said McGill and killer did not know each other. She was able to tell police that the man jumped out of the bushes, stabbed her several times and then ran. She also gave police a description of her attacker before she died, saying he was a black man in his 30's with a "bad eye." He was last seen wearing a black hoodie sweatshirt.

Police detained a man with a similar description, obtained a search warrant and seized his clothes. But, they didn't have probable cause to arrest him and he has been released. Police have not ruled him out as a suspect.

Stephens points out, random attacks like this are extremely rare. He does not want people to live in fear, only to be aware of their surroundings.