The mass shooting that began at a trucking company in California earlier this week may have been inspired by the shooter’s suspicions of his trucker wife’s infidelity, investigators say.

The incident, which left six people dead including the shooter, happened in Bakersfield, California on Wednesday, September 12th and was the third deadliest mass shooting this year, behind the Florida and Texas school shootings.

According to the LA Times, the shooter, 54-year-old Javier Casarez, was in the final stages of a divorce filed last year and was fighting with his wife, 45-year-old Petra Maribel, over custody of their four children, as well as ownership of shared property, when he set out with a gun.

In the divorce filings, Casarez accused his wife of infidelity, writing that “we are getting divorced because my wife cheated on me. I would like for the judge to grant me a subpoena for me to see the text messages to whom my wife texted to,” reported KGET News.

Two of the numbers Casarez lists in the filings belong to people he shot and killed on Wednesday – 57-year-old Eliseo Cazares, who apparently worked as an independent trucker and was shot along with his daughter at the house on Breckenridge Road, and 50-year-old Antonio Valadez, who was shot inside the T&T Trucking company where officials believe he may have been employed.

“We believe it’s very possible the wife was forced to go to T&T Trucking with her estranged husband,” said Sheriff Donny Youngblood.

“It appears that the suspect targeted each of his victims. We know that the suspect and his estranged wife were in divorce proceedings. We know that she had filed for a change order in the proceedings very recently on child support and property. We don’t know if that is the catalyst but it certainly has the implications of domestic violence,” he continued.

“Sometimes these domestic violence cases morph into something really bad and we want to find out how the other players fit into that domestic violence issue,” Youngblood said.

“If you look at the time frame of when this occurred, from scene to scene to scene, it appears to me to be very calculated.”

Officials did discover that Casarez had received paystubs from T&T trucking as recently as November of 2017 and that his wife, though unemployed at the time of her death, had also listed her occupation as “trucker” on court documents.