Yesterday’s Crimes: DNA Profiles and the Murderers Who Might Be Zodiac

Can the same combination of new DNA profiles and open source genealogy databases that cracked the Golden State Killer case help track down the Zodiac Killer?

Cheri Jo Bates, an honor student and cheerleader, checked out three books on English composition from the library at Riverside City College early in the evening on Oct. 30, 1966. When she got into her green Volkswagen to drive home, the engine wouldn’t turn over. A man walked up to her car and offered some help. This apparent Good Samaritan was the one who pulled the wires from the VW’s distributor cap so her car wouldn’t start.

The next morning, a groundskeeper found Bates’ body facedown and fully clothed between two empty houses on the college campus. Her throat was slashed and she was stabbed. Police at the time told the press that there were no signs of a struggle, but that wasn’t entirely true.

Cherri Jo Bates (Image: Tom Voigt/

Bates clawed at her attacker, and she died with bits of his skin and hair under her fingernails. That hair and skin might contain the genetic code that could finally reveal the identity of her killer, and possibly even the Zodiac Killer.

After matching a DNA profile to an open source genealogy database led to the arrest of former cop Joseph James DeAngelo in the decades-old Golden State Killer/East Area Rapist case last month, other California law enforcement agencies are hoping to use the same methods to solve other notorious cold cases.

Vallejo police have submitted envelopes used by the Zodiac to a private lab to possibly obtain a new genetic profile of the killer from saliva on the backs of stamps and the envelope flaps. Vallejo police Detective Terry Poyser told the Sacramento Bee last week that he expects to have the results back in a few weeks, and will then dive into the genealogy databases to find the Zodiac or at least his close relatives.

There may also be a break coming soon in the Santa Rosa Hitchhiker Murders, a case with potential links to the Zodiac Killer.

“We can’t divulge our investigation techniques, but the boxes are open and we are taking a fresh look at it,” Sgt. Spencer Crum of the Sonoma County Sheriff’s says when asked about the eight unsolved murders of young women and girls around rural stretches of Santa Rosa in the 1970s.

Zodiac suspect Arthur Leigh Allen lived in a trailer close to where the bodies were found when he studied biological sciences at Sonoma State from 1970-74.

In Riverside, Detective Adrian Tillett recently inherited the Cheri Jo Bates case from another detective who had been promoted.

“I’m definitely going to look into whatever I can do to help solve this case,” Tillet says. “There’s definitely a lot of interest.”

Chronicle crime reporter Paul Avery linked the Bates murder to Zodiac in “An Exclusive Report” on Nov. 16, 1970.

“A number of chilling similarities link the savage Oct. 30, 1966 knife slaying of 18-year-old Cheri Jo Bates with Zodiac—whose most recent boast is that he has killed 14 persons,” Avery wrote. Then as well as now, only five murders have been officially attributed to Zodiac, but the killer boasted of killing as many as 35 people in his infamous letters.

The connection to Zodiac came in the form of carbon copies of a typed confession letter sent to the Riverside Press-Enterprise and another addressed to “Homicide Detail.”

“I am not sick. I am insane. But that will not stop the game,” the killer wrote, giving details of the slaying that only Bates’ killer would know. The talk of “the game” was eerily similar to language used the Zodiac’s later letters. More letters came in April and these notes were signed with a Z-like symbol.

The envelopes used in Riverside, with block printed scrawl that read “ATTN: Editor,” also resembled Zodiac’s letters to Bay Area newspapers. 

Decades later, analysts on the History Channel’s The Hunt for the Zodiac Killer, found that both Zodiac and the unknown Riverside suspect misspelled twitch as “twich.”

Arthur Leigh Allen and fellow Zodiac suspects Rick Marshall and Ross Sullivan have been placed in Riverside at the time of the Bates murder. Sullivan worked at the Riverside City College Library and reportedly disappeared for a few days after the murder.

In 1998, Riverside police were able to obtain skin, saliva and other samples from their top suspect in the Bates case, but later tests against the mitochondrial DNA taken from the hair and blood clot found in Bates’ hand ended up clearing him.

In November 2016, Detective Jim Simons, Detective Tillett’s predecessor on the Bates case, told the Riverside Press Enterprise that he and Senior Forensic Technician Liane Velin were preparing to submit the hair and skin samples to a private lab. The results of those tests are unknown and Detective Tillett could not comment further on the investigation. 

In our new post-Golden State Killer reality, however, we might soon know the identities of three different California murderers, or possibly just one.

CORRECTION: An earlier version of this story misidentified Ross Sullivan as the subject of Gary Stewart’s The Most Dangerous Animal of All: Searching for My Father… and Finding the Zodiac Killer (Harper, 2014). The subject of this book is Earl Van Best, Jr. 

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