Usama bin Laden and Anwar al-Awlaki may be dead, but their message continues to inspire terror. The arrest of Jose Pimentel, a 27-year old Dominican-born American citizen charged with plotting to blow up police cars, post offices, and U.S. soldiers returning from Iraq and Afghanistan, highlights several trends that trouble and puzzle American law enforcement.

The first is the extent to which American citizens continue to be radicalized here in America without traveling abroad or any apparent direct contact with the Al Qaeda militants who Pimentel allegedly told friends had inspired him. According to a 2010 study by the New York Police Department, 30 of 33 terrorist plots studied by the NYPD involved a would-be terrorist who was radicalized at home – 90 percent of them in the West.

The NYPD has been focused on this group of “jihadi” wanna-bes ever since 2007, when a report co-authored by Mitchell Silber, who now oversees the NYPD's intelligence analysts, first identified “home-grown” terror as a leading trend in terrorism cases.

Silber and other terrorism analysts have repeatedly warned that there were likely to be more "homegrown" plots ahead in Europe, the United States, Canada, and Australia.

Another trend of concern is the role of the Internet in their radicalization. At least three plots aimed at New York within the last three years were inspired by “Inspire,” the glossy on-line magazine published in English that was targeted to the audience Islamist militants most desire, Americans and other English-speakers who can blend into Western culture.

Inspire featured interviews with jihadi heroes and militant "self-help" articles like "How to Make a Bomb in the Kitchen of Your Mom." The police charge that Pimentel followed the recipe contained in that article in buying the ingredients for and assembling his own pipe-bomb. His effort was literally by the book.

There have been no more issues of Inspire since Samir Khan, another American citizen who edited and produced the magazine from his hide-out in Yemen, was killed in a drone attack last September along with his hero and “Inspirer,” Anwar al-Awlaki. But his legacy, his on-line magazine, lives on. And if the allegations against Pimentel are true, the magazine continues not only to “Inspire,” but to provide a deadly manual for those seeking to use terror to kill Americans at home and abroad.

A third trend of concern is the disproportionately large number of converts to Islam within the ranks of accused terrorists.
Mitch Silber and Karen Greenberg, a form executive director of the Center on Law and Security at New York University who now heads a similar new program at Fordham, say they don’t fully understand why converts to Islam increasingly feature in jihadist plots.

Is there something particularly insidious about the combination of the Hispanic "macho" culture among young males and conversion to Islam that drives such young men toward the most violent, extremist interpretations of the faith?

Could this group of American immigrants feel particularly marginalized and hence, be vulnerable to militant radicalization when they convert?

No one seems to know.

But Pimentel is hardly the first Hispanic convert to turn to terror. Among the first, and most notorious, was Jose Padilla, the Hispanic-American citizen radicalized in Chicago and arrested in 2002 for plotting to blow up the Brooklyn Bridge.
Another was New Yorker Bryant Neal Vinas, the son of Peruvian and Argentinean parents who became radicalized in the city before traveling to Pakistan in an attempt to link up with Al Qaeda and engage in violent jihad.

Another was Carlos Eduardo Almonte, a naturalized American who came from the Dominican Republic and converted to Islam. Last June, he was arrested and accused with another conspirator of conspiring to commit murder, kidnapping, maiming and mayhem in the name of God. They were arrested while trying to go to Somalia, where they intended to join an the Al Qaeda-affiliated, Somalia-based terrorist group called Al Shabab, or "the guys" in Arabic.

And now there is Jose Pimentel.

Now that Usama bin Laden is dead and Al Qaeda is under enormous pressure, there is tendency to dismiss terrorism as yesterday’s threat. Indeed, the NYPD’s large, well-funded counter-terrorism program that surveilled Pimentel since 2009, long before his violent words turned into potentially even more violent deeds.

Last August, the Associated Press began publishing a series of articles about how the NYPD has been collecting information about Muslims for its program. The thrust of the articles is that the NYPD intelligence programs use monitoring techniques that violate the First Amendment. The police, they claim, have conducted surveillance of entire Muslim neighborhoods, chronicling people’s daily activities, where they eat, socialize and pray. Police infiltrated dozens of mosques and Muslim student groups and investigated hundreds more, the reporters charge, based on NYPD documents and interviews.

The NYPD has denied violating New Yorkers’ civil rights and has said that its legal surveillance is required to keep New Yorkers safe. Mayor Mike Bloomberg went out of his way on Sunday night to praise the NYPD’s counter-terrorism program. Jose Pimentel is just the latest reminder of why.

Judith Miller is an award-winning writer. She is a Manhattan Institute Scholar and Fox News contributor.