Adding to the tragic narrative about underpaid farmworkers and the socioeconomic situation underpinning Monday's shooting in Half Moon Bay, we now learn that the triggering dispute that occurred between the suspect and his supervisor was over $100.

As NBC Bay Area reported late Thursday, shooting suspect Zhao Chunli became enraged Monday after being handed a bill for equipment damage from an earlier incident totaling $100. Zhao, who operated a forklift at California Terra Garden, believed that a coworker in a bulldozer had intentionally hit his forklift in the earlier incident, and that his coworker should have to pay for the damages.

About a half hour before the shooting took place, Zhao approached the supervisor, who was also a Chinese immigrant, disputing the charge. The supervisor allegedly told him he still had to pay, and then rode off on a bicycle. Not long after, Zhao retrieved his Glock handgun — which NBC Bay Area reports he had slept with under his pillow for two years — and shot both the supervisor and the coworker who had been driving the bulldozer in the collision.

The detail we learned yesterday from two witnesses, about Zhao appearing to laugh maniacally and hop on his forklift immediately after killing the two men, now takes on new meaning.

San Mateo County DA Steve Wagstaffe confirmed these details to Bay Area News Group, adding, "We have so much more to learn about this individual, about the victims and their families and the harm that’s been inflicted here."

The story of the shooting, in which seven people died and one man was critically injured, has shone some new light on the lives of farmworkers. Some of them at California Terra Garden were migrants from Mexico — including victim Jose Romero Perez, who was earning money to support a wife and four children in Oaxaca — while others were longterm U.S. residents like Zhao, who had a green card and had lived in the country for 11 years.

He and his wife lived together in one of the worker housing structures at the farm, though his wife did not work at the farm. Coworkers said they had a personal garden where they grew onions year-round.

Governor Gavin Newsom gave a press conference on Wednesday talking about the squalid conditions workers at these farms live in, discussing below-minimum wages of $9 per hour, and shipping containers converted into homes.

A spokesperson for California Terra Garden said workers there made $20 per hour and more, and that "Shipping containers doesn't reflect what's on property."

This latest detail about Zhao's motive further solidifies the story of trauma, alleged bullying, and long-simmering tensions between coworkers at the lowest rung of the socioeconomic ladder that led to this tragedy — and to the heinous actions taken by a possibly mentally ill and aggrieved individual.

Previously: Half Moon Bay Shooting Suspect Admits to Murders In Jailhouse Interview, Suggests He Might Have Mental Illness

Top image: In an aerial view, greenhouses are seen at a farm where a mass shooting occurred on January 24, 2023 in Half Moon Bay, California. (Photo by Justin Sullivan/Getty Images)