SAN FRANCISCO (AP) - The California mushroom farm where four people were killed Monday had another shooting last July where one manager attempted to kill another.

Court documents and a case summary from the San Mateo County District Attorney's Office show California Terra Garden manager Martin Medina was charged with attempted murder after he threatened to kill the other manager and then fired a gun into the man's trailer. The bullet went through the trailer and into a neighboring one. No one was injured.

Charging documents obtained by The Associated Press say that neighboring trailer was occupied by Yetao Bing and Ping Yang. Bing is the name of one of the four people killed at the farm on Monday.

Chunli Zhao has been charged with seven murders in Monday's shootings at California Terra Garden and another farm nearby where three people were killed.

California Terra Garden spokesman David Oates said Zhao was not involved in last summer's shooting.

The Bay Area News Group first reported the earlier shooting.

Zhao, 66, told KNTV-TV in a courthouse interview Thursday that he committed the fatal shootings. He said he wasn't in his right mind when he entered a mushroom farm where he worked in Half Moon Bay and shot and killed four people and seriously wounded a fifth. He then drove to a nearby farm where he worked previously and killed three more people, prosecutors said.

Zhao said he was bullied and worked long hours on the farms and that his complaints were ignored, the station reported.

Eric Hove, one of Zhao's attorneys, did not immediately respond to a phone message seeking comment.

Zhao spoke in Mandarin with the television station reporter during a 15-minute interview at a county jail in Redwood City. Zhao said he has been in the U.S. for 11 years and has a green card. He said he has a 40-year-old daughter in China and lived with his wife in Half Moon Bay.

Zhao told the station he bought the gun used in the killings in 2021 and didn't run into any obstacles when making the purchase. He was planning to turn himself in to authorities when he was spotted by deputies who arrested him Monday.

The shootings occurred Monday at California Terra Garden, previously known as Mountain Mushroom Farm, and nearby Concord Farms.

Oates, the California Terra Garden spokesman, confirmed Zhao lived on the farm along with his wife and said the farm has “no knowledge of any complaints by anyone on allegations of bullying.”

On Wednesday, San Mateo County District Attorney Steve Wagstaffe charged Zhao with seven counts of murder and one of attempted murder.

The charges against Zhao include additional allegations that could result in the death penalty or life in prison without parole, though Gov. Gavin Newsom has issued a moratorium on executions. Among those allegations are that Zhao used a gun, caused great bodily injury and killed multiple people.

The coroner's office named six of the victims: Zhishen Liu, 73, of San Francisco; Marciano Martinez Jimenez, 50, of Moss Beach, California; Aixiang Zhang, 74, of San Francisco; Qizhong Cheng, 66, of Half Moon Bay; Jingzhi Lu, 64, of Half Moon Bay; and Yetao Bing, 43, whose hometown was unknown.

The charging documents identify Jose Romero Perez as the other person killed and Pedro Romero Perez as the eighth victim, who survived the shooting.

The state's labor department is looking into possible labor, workplace safety and health violations at the farms where the shootings happened, a spokeswoman for the Department of Industrial Relations said Thursday. Newsom's office said some of the farmworkers told him they made $9 an hour and lived in shipping containers. The state minimum wage is $15.50.

“The conditions farmworkers shared with the Governor ... are simply deplorable. Many workers have no choice but to tolerate the conditions provided to them by their employers,” Newsom spokesperson Daniel Villasenor said in a statement.


Gao reported from Los Angeles.