The shooting that left four dead at a California mushroom farm on Monday was at least the second time an employee tried to kill a coworker on the property. 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. Charging documents obtained by The Associated Press show the second trailer was home to Yetao Bing, who was killed in Monday’s shooting.