One question is at the heart of every person wondering how to find a terrorist: where do you begin the hunt? How did guys like us take the smallest piece of information and use it to find that ISIS or Al Qaeda leader and pinpoint him to a specific point in the desert?

Finding terrorists who have spent their lives eluding U.S. forces is an art, not a science, and there were only a handful of intelligence professionals who could successfully do it night after night. We could find anyone if given the opportunity - and our multimillion dollar drones gave us the ability to do it with precision.

Every hour wasted debating was another minute the bad guy had to adapt. We needed to move at the speed of war because the enemy wasn’t waiting.

As targeters we had to be historians, reporters, and prophets at the same time.

There was no magic formula to finding a terrorist. It was a combination of things and every target was unique in its own way. The elite special operations task force I worked for had several intelligence teams, which operated in different parts of the world, swooping in and out under the cover of night.

As targeters we had to be historians, reporters, and prophets at the same time. Not only did we need to understand a target so well that we could recite an enemy’s life story, but we were also constantly providing up-to-date assessments to commanders and others high up in the U.S. government and ultimately predicting a target’s next move.

Let’s say our mission was to find a terrorist named Ahmed Talib Umar al Tikriti - a composite of guys that I chased. And all my team knew when we landed in Iraq and set up shop in a secret bunker was one single thing: that he was the senior administrative emir (leader) for Al Qaeda in the Diyala province, the eastern part of Iraq.

Every terrorist had his vulnerability. These guys were human after all. I had to get into the mindset of a terrorist operator, think like he did.

I started with the target’s full name. Names are hidden gems in the Middle East -- and usually overlooked. Men are named after their forefathers, so the second name would come from his father and the third from his grandfather, and then a part would also tell you where, geographically, they were from. Now I had at least one point on the map to begin.

I knew that Ahmed – aka Abu Samir (every terrorist had what we called an “Abu name,” with Abu meaning “father of” and then their first son’s name) – wasn’t the top guy in the organization, but targeting him served a specific need. As admin emir, he was the group’s accountant. He knew where money flowed - and how we could stop it.

One thing we had to be careful about were kunyas - fake names terrorists give themselves to hide from trackers like us.

We diagrammed full names and families as a baseline for our search. An analytic tool helped see inner circles, organize my findings, and manually draw quick diagrams and charts about his world, particularly who else I might need to go after to get the target in question.

Following other raids of targets I knew were in Ahmed’s inner circle allowed us to sift through their cars, homes, phones…everything we could get our hands on. And we used it to look for pressure points (religion, financial motivations, family). There’s no more useful leverage than family in these parts of the world.

Then we started to build triggers on the target - places they visited, even if they knew that U.S. forces were following them.

Our startpoints were numerous at the early stage of the hunt. We collected additional ones outside of a target’s family, looking at any information we might glean from internet sites, reports, and databases. Locations could be anything: a distant relative’s house, local stores, historical sites tied to other members of his immediate group.

Sometimes the key to finding our target could be the simplest thing: an office building he used to work at years before he turned extremist; a café he was known to frequent; the mosque where he prayed. I was also looking for key things such as his education or distinguishing features like a broken nose or a limp.

While this was going on, our resident signals intelligence specialist poured through signal intelligence related to a target - any communications, online propaganda videos, whatever he could dig up. With a few mouse clicks, I could access almost any necessary intelligence file from various intelligence and law enforcement agencies back in Washington.

With all that in place and a mission approved, we started the hunt. Following leads, connections, and relationships until we’d catch a break – a trip into the middle of nowhere in a white bongo (a pickup truck), multiple stops at markets without a single purchase, a visitor who suddenly appeared one day out of the blue.

All stops we witnessed through our unblinking “eye in the sky” – our drones – were logged and cross-referenced with our database for suspicious connections, other targets who might have used the locations before.

Using all of that information, in real-time, including pictures of associates and family members we could supply to the assault force on the ground, once we had eyes on the right people who were a degree or two of separation away from the target, we’d almost inevitably get to them – provided we had done the right intel work, were patient enough to see it through, and didn’t have some disruption in pursuit like bad weather or losing a target in a busy urban center.

Now through our understanding of Ahmed, we watched a man who exhibited the same signature as he walked into the house at one of the stops we logged and then minutes later emerge again with another guy. As they retrieved something from their car, I noticed something: one of the men walked with a large limp. About the same time, we got some separate intel that Ahmed was in town visiting his old house and had recently hurt his leg.

It was time to act. I argued to the commander to capture, though it was ultimately the target’s decision if he wanted to go out quietly -- or with a bang.

Because Ahmed was an admin guy, he could provide a lot of information on senior leadership as well as take us to others.

And then .. 99 percent of the time we captured targets. The other times, we shot them down with a hellfire. The criteria for kills varied. What would killing this person mean to the network or even to the local authorities? How would it help us? Would it make things worse?

In the case of Ahmed, the commander agreed with my recommendation. And shortly after, the assault force was up in Blackhawks, racing toward Ahmed. Within hours, he was ours.