Police discovered the bodies of Jennifer DuPras, 55, and her 88-year-old mom, Cynthia Houk, in Houk's northwest Fresno home on Dec. 11
California authorities continue to investigate the 2017 double slaying of a former elementary school principal and her mother, both of whom were found shot multiple times in the mother’s home, PEOPLE confirms.
Police discovered the bodies of Jennifer DuPras, 55, and her 88-year-old mom, Cynthia Houk, in Houk’s northwest Fresno home on Dec. 11. They were found about 4 p.m. after DuPras didn’t show up to lunch with former colleagues earlier that day. DuPras’ last contact with friends and family was on Dec. 9.
Investigators have since ruled out robbery as a motive and believe DuPras and Houk may have known their killer.
“We didn’t find any points of forced entry, no broken windows or smashed-down doors,” Tony Botti, with the Fresno County Sheriff’s Office, tells PEOPLE. “It is possible they could have maybe known this person and let them in the house.”
Adding to the mystery, a car was set on fire at Houk’s home prior to the shootings and the headquarters of a French non-profit where DuPras worked also burned down, authorities say.
The slayings have unnerved the residents of the usually quiet neighborhood, Botti says: “We don’t have a ton of calls over there and nothing like a homicide. Something like this really kind of rocked that neighborhood.”
“It’s terrible,” Botti says of the deaths. “That is why we really want to get closure for this family.”
After obtaining numerous snippets of neighborhood video, police now suspect Houk and DuPras — a former principal at Washington Elementary in nearby Kingsburg — were killed on Dec. 9, two days before their bodies were found.
The videos, released this week by the Fresno sheriff, show a white crew-cab Chevrolet Colorado pickup truck leaving Houk’s neighborhood.
The truck has alloy rims, a towing hitch, a toolbox and a decal sticker on the rear portion of the bed.
The footage is dated Dec. 9.
“We came across this one truck in different places,” Botti explains. “One was leaving the neighborhood and the others were on surface streets getting out of the neighborhood. … We know that nobody in that area lived there and owned that truck. Based upon it leaving the area where the home was, that gives us information that it didn’t fit and [was] probably our suspect vehicle getting away.”
One thing the videos do not show is the truck’s driver or license plate.
“That is why we are trying to stir up some public’s help,” Botti says.
As to what the motive might be, Botti says, “A lot of the speculation around here points back to somebody close to them, either family or friend that had something personal going on.”
Botti says police have not yet identified any suspects. “We still continue to look at everybody,” he says. We don’t want to narrow our focus so much that we might miss something.”
At the time of the shootings, DuPras was going through a divorce, he says.
“We spoke to him shortly after the homicide and there is no evidence right now to point directly to him,” he says of DuPras’ estranged spouse, Alan DuPras, whom PEOPLE could not reach for comment.
According to local media, Jennifer DuPras retired from her education job in 2017, saying she was going to volunteer and travel as well as take care of her mother.
Since the slayings, detectives have served multiple search warrants at various locations, including at Alan’s home. They have also scoured through dozens of surveillance videos from the neighborhood.
“Based upon all the images and video we collected, we have been able to puzzle it together and look at this three- or four-mile course this vehicle appears to have taken during the timeframe in which the homicide happened,” Botti says. “Everything is going to lead us back to Dec. 9.”
Anyone with information about the shootings is urged to call 559-600-8400 or 559-498-STOP or go online.