The perimeter of the courthouse is surrounded by tight security, which has been continually upgraded since the 1995 Oklahoma City bombing The sidewalk in front of the courthouse is lined with white concrete barriers that would stop any would-be car bomber from reaching the building. Since that time, the lane running between the courthouse and a newer courthouse across the street has been closed to traffic, except vehicles dropping off judges or making deliveries. A guard booth now stands at the top of the street, where U.S. marshals control a new hydraulic-powered metal barrier. The hydraulic barrier is lowered to let the vehicle through and then immediately pops up again. In next few weeks, dozens of six-foot tall, green metal columns, known as bollards, will be installed around the courthouse perimeter, replacing the Jersey barriers.
Security is another reason.
The third floor of the Foley Square courthouse is connected by an enclosed metal bridge to the Metropolitan Correctional Center. It is the shortest and most protected distance for daily defendant travel. In the courtroom, their shackled ankles are hidden from jurors' eyes by black drapes hanging from the lawyers' tables. Appearances count, and it could be considered prejudicial to let the jurors see the defendants in leg irons. For the same reason, the defendants wear traditional tunics instead of prison uniforms.