[1] Beginning in 1969, the Wah Ching fought a war with the Suey Sing Tong for control of Chinatown's gambling, loan-sharking and extortion rackets.

[14][15] During the mid-1960s, Wah Ching established themselves in Southern California, mainly around Chinatown, Los Angeles and the San Gabriel Valley.

[16] During this time, Wah Ching in Los Angeles operated illegal gambling houses, brothels, extortion rackets, and loan-sharking.

In 1991, Danny "Ah Pai" Wong, the leader of Wah Ching, was shot and killed by Wo Hop To (WHT) hitmen from Seattle Chinatown.

After law enforcement cracked down on the Wo Hop To around 1992, former Wah Ching members who had defected to the Wo Hop To founded the Jackson Street Boys, a gang based in San Francisco's Chinatown which resumed what a SFPD officer described in 2000 as "the same stuff on a smaller scale and without the same visibility", including extortion of local merchants and operating gambling dens.

Wah Ching's move from its original home in the Bay Area to Southern California is probably one of the sources of the disputes over gang turf.

[20][19] On June 2, 2007, Anh Duoc Nguyen, a member of Monterey Park-Side Wah Ching shot at five people in Westminster's Bowling Green Park, severely injuring one.

Here is the chronology of violence: March 9, 1972 when Harry Quan (or Kwan) was shot from a car with a .32 caliber automatic as he stood with a group of youths in front of 815 Stockton Street, location of the Police Athletic League.

Harry Ng, murdered in his Kung Fu studio March 13, 1972, is believed to have been a courier between the Wah Chings and a mysterious person in Hong Kong known only by a code name.

On the night of August 12, at a service station at 19th Avenue and Irving Street where he was employed, Wayne Fung was killed by seven bullets from a .38 caliber automatic.