SAN MATEO -- The FBI said Friday it is seeking a cold tip that might lead them to a key witness in the 1976 Gypsy Hill killings of five women on the Peninsula that spurred the formation of a task force earlier this year when a Reno slaying was tied to the mysterious killer four decades later.

Investigators are seeking a white male in his late 20s to early 30s at the time of the killings, who was in San Mateo County between January and April of 1976 and drove a vehicle with Nevada license plates.

While the tip is vague, authorities hope it will jog the memory of someone in the area and revitalize the investigation, in the same way that the Reno victim revelation inspired a task force announced in March, composed of the FBI, the San Mateo and Washoe County sheriff's offices, and Daly City, Pacifica, South San Francisco and Reno police departments.

Paula Baxter, Denise Lampe, Michelle Mitchell, Tanya Marie Blackwell, Veronica "Ronnie" Cascio, and Carol Lee Booth "Beedy" -- whose ages ranged between 14 and 26 -- were killed in 1976. In March, authorities revealed that Mitchell, a University of Nevada-Reno student, is thought to have been contacted Feb. 24, 1976 by the Gypsy Hill killer in the middle of the Peninsula slayings, which started at the beginning of that year.

Anyone with information can confidentially contact the FBI San Francisco field office at 415-553-7400, then press "0" and mention the Gypsy Hill cases.