Charges have been dropped against 11 of the 15 members of Turkish President Recep Erodgan’s security team who were accused of beating protesters during a visit to Washington, D.C. last year. The brutal attack last May sent nine people to hospitals, and was widely condemned by U.S. authorities and caused a diplomatic rift between the two countries. Charges were dropped against four individuals in November, and then against seven others on Feb. 14—the day before then-Secretary of State Rex Tillerson flew to Ankara for talks with Erdogan. The U.S. considers Turkey a key ally in the fight against ISIS. Officials insisted late Wednesday that charges haven’t been dropped for political reasons, saying they were dropped after it became clear investigators had misidentified some of the suspects and failed to develop enough evidence against others.