From a Wall Street Journal story by Drew Hinshaw, Joe Parkinson, and Brett Forrest headlined “‘You Are Completely Alone’: Inside the Infamous Russian Prison Holding Evan Gershkovich:

At Lefortovo prison, the interrogations start with the clanging of metal.

Guards patrolling hundreds of cells at the sprawling facility on the outskirts of Moscow bang their keys together to signal that an inmate is being escorted from their cells to an interrogation room, according to former prisoners, their families and their lawyers. Others snap their fingers in the hallways, where fluorescent lights buzz day and night, a warning there should be no other prisoners in sight and as few personnel as possible.