Stealth being stealthy, picking locks

They turned the corner, still trying to pass off their paperwork, and Stealth dropped down from the ceiling.
The colonel’s office was locked with a Medeco3 dead bolt, but she had seen schematics of the tumbler mechanism at a seminar in Las Vegas several years earlier. Six minutes of work and she was inside the reception area of Shelly’s office. The door closed behind her without a sound and she reengaged the lock.

Excerpt From Ex-Patriots, pg 390
Peter Clines
https://books.apple.com/us/book/ex-patriots/id585738393