Maureen Louise Sterling and Yvonne Lisa Weber, both 12-year-old Herbert Slater Middle School students, disappeared around 9 pm on February 4, 1972, after visiting the Redwood Empire Ice Arena. They were last seen hitchhiking on Guerneville Road, northwest of Santa Rosa. Their bodies were found December 28, 2.2 miles north of Porter Creek Road on Franz Valley Road, down a steep embankment approximately 66 feet off the east side of the roadway. A single earring, orange beads and a 14-carat gold necklace with cross were found at the scene. The cause of death could not be determined from the skeletal remains.
Santa Rosa Junior College art student Kim Wendy Allen, 19, was given a ride by two men on March 4, 1972, from her job at Larkspur Natural Foods to San Rafael. They last saw her at approximately 5:20 pm hitchhiking to school near the Bell Avenue entrance to Highway 101, northbound, carrying a large wooden soy barrel with red Chinese characters on it. Her body was found the following day down an embankment in a creek bed twenty feet off Enterprise Road in Santa Rosa. The victim had been bound at the ankles and wrists, raped and slowly strangled with a cord for an estimated thirty minutes. Semen was recovered from the body and a single gold loop earring was found at the site. Markings at the top of the embankment and a possible leg impression in the loam indicated the assailant likely slipped or fell while throwing or transporting the body. The two men who gave her a ride, one of whom was given and passed a polygraph test, were ruled out as suspects.
Lori Lee Kursa, 13, a Lawrence Cook Middle School student, had been reported missing by her mother on November 11, 1972 after disappearing while they shopped at a U-Save and was last seen on November 20 or 21 in Santa Rosa while visiting friends, having deliberately run away. She had been known to hitchhike occasionally. Her frozen remains were located on December 14 in a ravine approximately fifty feet off Calistoga Road, northeast of Rincon Valley in Santa Rosa. The killer had thrown the body at least thirty feet over an embankment. The cause of her death was a broken neck with compression and hemorrhage of the spinal cord. The victim had not been raped and likely died one to two weeks prior to discovery. A possible witness to her abduction later came forward stating that on an evening somewhere between December 3 and 9, while on Parkhurst Drive he saw two men push a girl fitting Kursa's description into the back of a van driven by a Caucasian man with an Afro-type hairstyle. The vehicle then sped north on Calistoga Road.
Carolyn Nadine Davis, 14 years old, ran away from her home outside Anderson in Shasta County on February 6, 1973 but disappeared July 15 after being dropped off by her grandmother at the Garberville Post Office. She was last seen hitchhiking that afternoon near the Highway 101 ramp, southbound, in Garberville. Her body was discovered on July 31 just three feet from where the remains of Sterling and Weber had been recovered seven months prior. Cause of death was strychnine poisoning 10–14 days before discovery. It could not be determined if she had been raped. Investigators postulated that her body had been thrown from the road as the hillside brush appeared undisturbed.
Theresa Diane Smith Walsh, 23, of Miranda, was last seen on December 22, 1973, at Zuma Beach in Malibu, intent on hitchhiking to Garberville and joining her family for Christmas. Her partially submerged body was found six days later by kayakers in Mark West Creek. She had been hogtied with clothesline rope, sexually assaulted, strangled and was determined to have been dead approximately one week. Due to recent heavy rains in the area, high water marks suggested the body could have drifted several miles.
On July 6, 1979, skeletal remains were found in a ravine off Calistoga Road approximately one hundred yards from where the body of Lori Lee Kursa had been recovered seven years earlier. Due to the age of the remains, authorities initially believed them to be those of Jeannette Kamahele until a comparison of dental records later proved negative. The victim had been hogtied and her arm fractured around the time of her murder but there was no other evidence to establish a cause of death. It was determined that the unidentified victim was approximately 19 years old, wore contact lenses, had red or auburn hair and at one time had broken a rib which was healed by the time of the murder.
Lisa Smith, 17, of Petaluma was last seen at about 7 pm on March 16, 1971, hitchhiking along Hearn Avenue in Santa Rosa. On March 29, The Press Democrat reported that a girl using the name "Lisa Smith" had recently been released after being treated at Novato General Hospital for injuries the victim claimed were sustained after being picked up by a man while hitchhiking and beaten. It was never determined if this was the same Lisa Smith. Her body was never found and Smith is officially a missing person.
Jeannette Kamahele, 20, a Santa Rosa Junior College student, was last seen on April 25, 1972, hitchhiking near the Cotati on-ramp of Highway 101. A friend witnessed her likely abduction and reported that she entered a faded brown Chevrolet pickup truck fitted with a homemade wooden camper and driven by a 20- to 30-year-old Caucasian male with an Afro hairstyle. Her body has never been found.
In 1975, the Federal Bureau of Investigation issued a report stating that fourteen unsolved homicides between 1972 and 1974 were committed by the same perpetrator. These comprise of the six found victims (as of 1975) and the following:On May 29, 1973, the body of 20-year-old Rosa Vasquez, last seen May 26, was found strangled near the Arguello boulevard entrance at Golden Gate Park in San Francisco. The victim had been thrown seven feet off the roadway into some shrubs. Vasquez had been a keypunch operator at Letterman General Hospital on the Presidio.
Yvonne Quilantang, 15, was found strangled in a vacant Bayview district lot on June 10, 1973. She was seven months pregnant.
Angela Thomas, 16, was found July 2, 1973, smothered on the playground of Benjamin Franklin Junior High School in Daly City. She had last been seen the previous evening at the Presidio of San Francisco. A locket was recovered near the body.
24-year-old radiographer Nancy Patricia Gidley, last seen at a Rodeway Inn motel on July 12, 1973, was found strangled behind the George Washington High School gymnasium three days later. The victim was unclothed except for a single fish-shaped gold earring and was determined to have died within the previous 24 hours. Gidley had served four years in the Air Force and told friends and family in Mountain Home, Idaho that she intended to become a freelance writer for the San Francisco Chronicle and was going to San Francisco to be the maid of honour at the wedding of a friend from Hamilton Air Force Base, all of which proved false.
Nancy Feusi, 22, disappeared after going dancing at a club in the Sacramento area. Her remains were found on July 22, 1973, in Redding. She had been stabbed to death. In 2011, one of Feusi's five children, Angela Darlene Feusi McAnulty, was convicted of torturing, beating and starving to death her 15-year-old daughter Jeanette Marie Maples. McAnulty became the second woman ever sentenced to die in Oregon and the first since the 1984 reinstatement of the death penalty.
The body of 21-year-old Laura A. O'Dell, missing since November 4, 1973, was found three days later in bushes behind the boathouse at Stow Lake in Golden Gate Park. O'Dell's hands were tied behind her back and the cause of death appeared to be from head injuries or strangulation.
Brenda Kaye Merchant, 19, was found stabbed to death in a ditch February 1, 1974, in Marysville.
On September 29, 1974, the strangled body of Donna M. Braun, 14, was found in the Salinas River near Monterey.
The unapprehended Zodiac Killer is a suspect. due to similarities between an unknown symbol on his January 29, 1974 "Exorcist letter" to the San Francisco Chronicle, in which he claims 37 victims, and the Chinese characters on the missing soy barrel carried by Kim Allen, as well as stating an intention to vary his modus operandi in an earlier November 9, 1969 letter to the San Francisco Chronicle: "I shall no longer announce to anyone. when I comitt my murders, they shall look like routine robberies, killings of anger, + a few fake accidents, etc." (sic)
Arthur Leigh Allen, of Vallejo, owned a mobile home at Sunset Trailer Park in Santa Rosa at the time of the murders. He had been fired from his Valley Springs Elementary School teaching position for suspected child molestation in 1968 and was a full-time student at Sonoma State College. Allen was arrested on September 27, 1974, by the Sonoma County Sheriff's Office and charged with child molestation in an unrelated case involving a young boy. He pleaded guilty on March 14, 1975, and was imprisoned at Atascadero State Hospital until late 1977. Robert Graysmith, in his book Zodiac Unmasked, claims that a Santa Rosa County sheriff revealed that chipmunk hairs were found on all of the Santa Rosa Hitchhiker victims and that Allen had been collecting and studying the same species. Allen was the main suspect in the Zodiac case from 1971 until October 2002, ten years after his death, when his DNA was compared to a partial DNA profile obtained from saliva recovered on the underside of a postage stamp and envelopes from verified Zodiac letters. Results were a conclusive non-match. Fingerprints in blood recovered from the taxicab of Zodiac murder victim Paul Stine, a writer's palm print found on the Zodiac letter of January 29, 1974, and handwriting exemplars further ruled out Allen as Zodiac.
After his capture for similar crimes in Washington, Colorado, Utah and Idaho, Ted Bundy was suspected in the murders. Bundy had spent time in neighboring Marin County, but was ruled out by a Sonoma County detective in the 1970s and again in 1989. Detailed credit card records and known whereabouts of Bundy reveal he was in Washington on the dates of some of the disappearances.
Fredric Manalli, a 41-year-old Santa Rosa Junior College creative writing instructor was suspected when, after his August 24, 1976 death in a head-on collision on Highway 12, sadomasochistic drawings he had created depicting former student Kim Wendy Allen were discovered among his belongings. Kenneth Bianchi and Angelo Buono, Jr., the Hillside Stranglers of Los Angeles, were also considered suspects at one time.
These cases represent eight of 54 total unsolved homicides between the years 1970 and 2006 within the jurisdiction of the Sonoma County Sheriff's Office. In 2011, cold storage DNA from some of the cases was submitted to Combined DNA Index System (CODIS), a national DNA database.