Fabian Richter is the kill list target in Mission 3: Spy Academy. Luckily, Richter is at the meeting you are supposed to spy on for the main objective. To complete the Mission 3 Kill Challenge in Sniper Elite 5, you must kill Richter using a stealth takedown.
Mission 3 Kill Challenge Guide
In order to take down Richter, you must first make your way to the top of the Abbey, where the meeting is taking place in Mission 3. Finding the meeting is the main objective, so once you gather the intel or find the meeting spot, you can complete the Kill Challenge.
How to find Richter
Once you get to the meeting spot, there are several entrances and ways to spy on the meeting. There are four doors to the room, but all require the meeting room key or a satchel charge. Opening these doors is more likely to alert Richter. The best way to go is to make your way to the east side outside of the meeting room. There will be a room with a guard and a ladder in the middle. You can take out the guard and climb the ladder to spy on the meeting.
How to kill Richter with a Stealth Takedown
The easiest way to kill Richter with a Stealth Takedown is to lure him out of the meeting room. You can either throw a bottle or explosive outside the meeting room to make him investigate. Be sure to stay out of view of any guards coming to investigate. If Richter leaves the meeting room, sneak up on him and press Triangle (PlayStation), or Y (Xbox) to execute a stealth takedown.
Be sure to check the mission objectives in the start menu before trying to kill Richter. It is possible to fail the Kill Challenge by entering combat and alerting guards, even far away from Richter. Guards investigating does not seem to trigger this, but a lot of combat during the mission can cause you to fail the Kill Challenge.
Mission 3 Kill Challenge Reward
Completing the Kill Challenge in Mission 3 rewards you with the Pistole 08, a pistol with great range and an optional 3x sight.
For more Sniper Elite 5 guides like this one, check out How to kill Ehrlich using a rat bomb in Sniper Elite 5 on Pro Game Guides.