DeAngelo, also believed to be the Visalia Ransacker, has already been charged with several murders, and could soon be charged with Claude Snelling's killing in 1975.
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They've recommended the Tulare County District Attorney's Office charge DeAngelo with the crime, and right now, the DA's office has the case under review.
Meanwhile, the Tulare County Sheriff's Office cold case unit confirms DeAngelo is on their short list of suspects in the murder of a Visalia teen less than a year before.
15-year-old Jennifer Armour was supposed to meet her friends to go to a high school football game, but she never showed.
She was last seen walking in the area of Demaree Street and College Avenue.
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More than a week later, her body was found in the Friant-Kern Canal, south of Woodlake.
There's very little physical evidence in the case, but for the past several years, Dempsie says they've looked into the possibility that the Visalia Ransacker killed Armour.
So once DeAngelo was identified as the Ransacker, he was added to the list of suspects.
"The Visalia Ransacker was very active in the area where Jennifer was last seen," Dempsie said. "So that coupled with his knowledge of the city of Exeter, having worked in the city of Exeter, and her body being found not far north of Exeter, we're certainly going to find out everything we can about him."
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But the list of suspects in Armour's murder also includes Oscar Clifton, who is now dead but was tried and convicted of murdering 14-year-old Exeter teen Donna Richmond in 1975.
Dempsie says he's reviewed the Richmond case to see if the deaths are connected.
That's still undetermined.
"It's something that we are looking at simply because we have two young girls that were killed within a year of one another, 13 months of one another in close proximity to one another," Dempsie said.
Dempsie says Armour's family still lives in the Visalia area, and he keeps them informed of any updates in the case.
But right now, there aren't many, and the details surrounding her disappearance and killer remain a mystery.
Deangelo will be back in court in September.
Full coverage on the Golden State Killer and the arrest of Joseph James DeAngelo here.