On July 5, police in Torrance, Calif., arrested ex-convicts Levar Haney Washington and Gregory Vernon Patterson on suspicion of committing a string of bank robberies in the Los Angeles area from May 30 to July 3. It was more than just a successful end to a bank robbery investigation; the arrests also marked the beginning of what appears to be the latest investigation into indigenous terrorism in the United States. Following the arrests, police searched Washington's apartment for evidence linking the two men to the robberies. Instead, they found materials linking the subjects to a militant Islamist group plotting attacks in the Los Angeles area. Among the items found in the apartment were bulletproof vests, "jihadist materials" and a target list. The list includes the El Al airline ticket counter at Los Angeles International Airport; Jewish synagogues in the Westside area of Los Angeles; California National Guard armories in west Los Angeles, Manhattan Beach and Torrance; and U.S. Army recruiting centers in Long Beach, Torrance and Harbor City. Several other reports have suggested that a note detailing the group's need for money and explosives was found with the target list. And on Aug. 2, federal and state officials arrested another man, Hammad Riaz Samana, in relation to the case. The details of the plot are still unraveling, but what is known is that both Washington and Patterson were former California prison inmates who converted to Islam and joined a radical Islamist gang while serving their sentences. The name of the gang is Jamiatul Islam Is Saheeh (JIS) — the "Assembly of Authentic Islam" — and they are one of several Islamist gangs known to be active within the California penal system. Prisons offer fertile ground for the cultivation of militancy. Threats from other prisoners, racist divisions and a shortage of positive social networks all come together to make gangs a very appealing — and almost necessary — aspect of prison life. Combine this with the scarcity of resources, budget priorities and translation difficulties typical to most counterterrorism operations and the result is a problem that is far outpacing efforts to contain it. Several examples of Islamist recruitment inside prisons indicate this is not a temporary problem. Would-be dirty bomber Jose Padilla is believed to have been radicalized during his 10 months in a South Florida prison. Europe also is far from immune to the threat posed by Islamist recruitment inside prisons. Would-be shoe bomber Richard Reid converted to Islam in a British prison. And, as STRATFOR has noted, France's prison population is largely composed of young Muslim men. The majority of Muslim prisoners are not interested in becoming terrorists, but it only takes a few. The Los Angeles JIS cell was apparently not connected to al Qaeda because it had to raise its own capital through bank robberies to fund its planned attacks. This is the type of grassroots sympathizers that Osama bin Laden and company are attempting to mobilize. Combating Islamist recruitment in prisons will be no easy task. America's prison population is the second largest in the world, and the push to join a prison gang is enormously powerful. Prisoners have few liberties, and the ones that they do have are vigorously defended by rights groups and the prisoners themselves. Therefore, any change in policy is bound to be met with resistance. The good news is that extremist gangs are not unknown to corrections officials, who are the ones most likely to face the results of violence plotted within prison walls. A substantial intelligence network exists to cover prison gangs and their activities. The difficulty, as with other coordinated counterterrorism operations, is in getting the right data to the right people. For the United States to remain safe from large-scale jihadist attacks planned in prisons, there will have to be better intelligence-gathering, improved data analysis and, as we have seen in the Los Angeles case, effective police work and a bit of good luck.