Tucked away in the middle of The Washington Post Saturday was an extensively reported story about how recent Islamic converts were key players in recently foiled terrorist attacks in Germany. The story starts on the front end discussing what "counterterrorism officials and analysts" are saying and follows up on the back end with a rebuttal of sorts from religious leaders in Germany's Muslim community. For one reason or another I get the sense that those reporting this story spent less time in the mosques and more time on the phone with law enforcement and public safety officials and thinkers who watch things like this:

In Copenhagen, a convert is among four defendants who went on trial this month for plotting to blow up political targets. In Sweden, a webmaster who changed his name from Ralf Wadman to Abu Usama el-Swede was arrested last year on suspicion of recruiting fighters on the Internet. In Britain, three converts -- including the son of a British politician -- are awaiting trial on charges of participating in last year's transatlantic airline plot.

"The number of converts, it seems, is definitely on the rise," said Michael Taarnby, a terrorism researcher at the Danish Institute for International Studies. "We've reached a point where I think al-Qaeda and other groups recognize the value of converts, not just from an operational viewpoint but from a cultural one as well."

There is a lot of psychoanalysis later in the story about Islamic converts' "zeal to prove their newfound faith." It starts out with the slightly radical but nonviolent mosques in their hometowns, but then come the visits to the madrassas in the Middle East. And then al-Qaeda has yet another suicide bomber, according to the analysts:

Converts are a tiny subset of the Muslim population in Europe, but their numbers are growing in some countries. In Germany, government officials estimated that 4,000 people converted to Islam last year, compared with an annual average of 300 in the late 1990s. Less than 1 percent of Germany's 3.3 million Muslims are converts.

While religious leaders emphasize that most converts are law-abiding citizens who often promote interfaith understanding, the recent arrests in Germany prompted some lawmakers to suggest that police should keep converts under surveillance.

"Of course not all converts are problematic, but some are particularly dangerous because they want to demonstrate through extreme fanaticism that they are particularly good Muslims," Guenther Beckstein, interior minister for the state of Bavaria, said last week.

Here are some big questions that are left unanswered and would probably take more than three reporters a couple of weeks to figure out: Why do these people convert? Why the increasing numbers? And what are they converting from? Christianity? Agnosticism? Atheism?

Why would any of these converts turn radical? For the purposes of a story like this, it doesn't matter if 95 out of 100 converts stop at the madrassas. All we're talking about in this story is a handful of converts who have since been arrested for being involved in terrorism. This rough spiritual timeline from the so-called experts is nice, but we need more. These are tough questions that will require some tough reporting.