The strike of Emwazi is almost certainly the result of months of patient intelligence-gathering.
The NSA - America's primary signals intelligence agency - has been trying to intercept all communications from IS, in an effort to track its leaders and pierce the organization's secrecy.
But how do they do their intelligence-gathering?
Firstly drones in the sky - three Reapers were dedicated to the Emwazi kill mission alone - give analysts real-time intelligence and video of movement on the ground.
Then we can be sure there are human assets on the ground. Raqaa is the heart of the internecine Jihadi movement and the capital of the IS caliphate. The CIA will have tried to recruit sources in the city, possibly even from within the ranks of ISIS. That story may never be told. But it may have been the key to finding Emwazi.
Ultimately, however good his operational security, Jihadi John was going to be found and killed. It was only a question of timing.
If you work at the CIA, Friday the 13th was not so much a lucky day, but the day that patience paid off.
The only surprise surrounding the American strike on Mohammed Emwazi is that it took so long to track him down.
Undoubtedly, he was a primary target for US and British intelligence agencies. His taunting manner, his English-speaking role as a jihadi recruiter, his direct involvement in the murder of British, American, Japanese, Syrian and Iraqi citizens all put a target on his back.
We don't yet know whether he was killed, but there must be a degree of confidence for the Americans to announce it in this manner.
But it raises a further question: if British and American agents and analysts were able to pierce the operational security surrounding Emwazi, how long before they can reach their real prize?
For Emwazi is - or was - a symbol. His likely death doesn't change the battlefield.
The man the Americans really want to eliminate is the IS leader, Abu Bakr al-Baghdadi.
So there will be professional satisfaction at the CIA and MI6 for having located Emwazi. But no time to celebrate.
Hunting down al-Baghdadi will continue to be the greatest single mission for US and UK intelligence agencies.