Half Moon Bay is a coastal, agricultural, and tourist city approximately 30 miles (48 kilometers) south of San Francisco.

[2] Seven months earlier, a manager at California Terra Garden who was not Zhao allegedly opened fire with a handgun at a coworker's trailer following a dispute and was later charged with attempted murder and criminal threats, as well as shooting into an occupied dwelling.

[3][4] According to the vice mayor of Half Moon Bay, it is difficult for those who are undocumented or not in the country legally, including some of the workers at California Terra Garden and in the city's farming community at large, to seek help from local authorities.

A fifth victim who survived was airlifted by helicopter to Stanford University Medical Center near Palo Alto, with life-threatening injuries.

As responders were arriving at the scene, the gunman drove two miles (3.2 km) away to Concord Farms in a maroon SUV, where he fatally shot three more people.

[8] At approximately 4:40 p.m., the suspect, Chunli Zhao, who was a resident and worker at the first farm,[9] was found in his vehicle in the parking lot of the San Mateo County Sheriff's Office substation at 557 Kelly Avenue in downtown Half Moon Bay.

[8][1] The victims were identified as Yetao Bing, 43; Qizhong Cheng, 66; Zhishen Liu, 73; Jingzhi Lu, 64; Marciano Martinez Jimenez, 50; Jose Romero Perez, 38; and Aixiang Zhang, 74.