SAN RAFAEL -- Using space age technology, Marin Sheriff's Department investigators have identified a woman who was stabbed more than 40 times with an ice pick, burned using acetone as an accelerant and shot in the head before her body was abandoned in a field in 1979.

Sheriff's Lt. Rick Navarro said Monday that DNA taken from a hair of the victim matched the DNA of the mother and sister of Tammy Vincent who lived in the Seattle area.

Vincent, 17, was reported missing on Aug. 29, 1979 from King County, Wash. Her body was found on Sept. 26, 1979 in the Blackies Pasture area of Tiburon.

Investigators said the materials used to commit the murder were purchased at a Woolworth store on Market and Powell streets in San Francisco the evening before the murder..

They were purchased by a white male dressed in a white leisure-type suit and a young white female matching the description of the victim, according to Navarro.

The murder was classified as a "cold case" until Tiburon police asked the sheriff's office to re-open the case in 2001 and the murder victim's body was exhumed for skull reconstruction and DNA analysis of bones in June 2002.

Department of Justice DNA lab in Richmond was able to obtain only a partial degraded profile of the murder victim and was unable to identify Jan Doe's true name, Navarro said.

In May 2005, The National Missing and Exploited Children organization made a photograph of the victim using crime scene photographs, Navarro said.

In December 2006, the DNA lab decided to examine additional evidence to get a better DNA profile using a sexual assault kit and clothing. Some of those items were degraded except for a pubic hair, Navarro said.

The National DNA Database known as CODIS was searched and an identification was made using a DNA sample that was submitted to the University of North Texas DNA program for missing persons.

The University's DNA database also contained DNA samples of Tammy Vincent's mother and sister that had been submitted by the King's County Sheriff's Office in Seattle as a result of the Green River killings in that area. Tammy Vincent was then identified as the murder victim when the DNA samples matched.

Navarro said Vincent agreed in August 1979 to testify against several people whose businesses were under investigation in Kings County for operating prostitution and "tease and rip joints," Navarro said. Several people were arrested for pimping and pandering.

Vincent was transported to a secure location in Spokane, Wash. in August 1979 but she left, Navarro said. An investigation of the Kings County authorities indicated individuals with ties to San Francisco were involved in the prostitution activities, Navarro said.

Vincent's body was exhumed for the last time on Aug. 7 of this year and she was cremated and laid to rest three days later in Washington, Navarro said.

The murder investigation continues, Navarro said. Anyone with information is asked to call 1-888-898-5818.