Complex sentence: Safe Burglary Case 9/8/1876 Corrupt building contractors in Washington, D.C., were on trial for graft when bogus Secret Service agents working for the contractors placed damaging evidence into the safe of the district attorney who was prosecuting the ring.
Split into simpler sentences: Safe Burglary Case 9/8/1876 Corrupt building contractors in Washington, D.C. were on trial for graft when a safe robbery occurred. Bogus secret service agents, working for the corrupt contractors, placed damaging evidence into the safe of the district attorney who was prosecuting the ring.