The four conspired to wage war against the U.S. government through terrorism, kill armed service members and murder foreign officials, among other charges, according to the indictment.
Named in the indictment were Levar Haley Washington, 25, Gregory Vernon Patterson, 21, Hammad Riaz Samana, 21, and Kevin James, 29.
Prosecutors contend the plot was orchestrated by Washington, Patterson and Samana at the behest of James, an inmate at the California State Prison-Sacramento who founded the radical group Jamiyyat Ul-Islam Is-Saheeh.
Washington converted to Islam while serving three years in the prison for a robbery conviction.
According to the indictment, Washington pledged his loyalty to James "until death by martyrdom" and sought to establish a JIS cell outside prison with members with bomb expertise.
Washington, Patterson and Samana — who attended the same Inglewood mosque — allegedly conducted surveillance of National Guard facilities, the Israeli Consulate and several synagogues in the Los Angeles area as well as Internet research on Jewish holidays.
The attacks were to be carried out with firearms and other weapons, according to the indictment. Patterson allegedly bought a .223-caliber rifle in July.
To finance the attacks, prosecutors said, the three robbed a string of gas stations in Los Angeles and Orange counties.
The case arose after Washington and Patterson were arrested July 5 by police in Torrance, a suburb southwest of Los Angeles, for investigation of robbing the gas stations.
Federal and local counterterrorism officials began investigating after police who searched Washington's apartment in the robbery case said they found a list of possible terror targets.