Here's the suggestion of what Kerry should say to finish this exchange:
Kerry: Mr. Bush, why haven't we caught Al Zaqwari?
Bush: He hides
Kerry: Having worked as a prosecutor, I'm familiar with the idea that criminals hide. It's not a surprise. But we find them, we arrest them, and we bring them to justice. We do it with small police forces all over the nation.
You've deployed almost the entire US military, along with the resources of the CIA, and you can't find Osama bin Laden in three years? You can't find Zarqawi in three years?
These folks are industrious in the thread of suggestions linked above. I recommend you stop by if only to read it.