The Pentagon and the FBI have notified some of the families of the victims killed in 9/11 that five of the suspected terrorists behind the attacks may be spared the death penalty under the terms of potential plea agreements being weighed. The families were told of the development in a letter dated Aug. 1 and obtained by the Associated Press on Wednesday. “The Office of the Chief Prosecutor has been negotiating and is considering entering into pre-trial agreements,” the letter said. While no agreement “has been finalized, and may never be finalized,” according to the letter, “it is possible that a [pre-trial agreement] in this case would remove the possibility of the death penalty.” The 9/11 defendants referenced in the letter are Khalid Sheikh Mohammed, accused of masterminding the attacks, and four other defendants being held at Guantanamo Bay. Speaking to the AP, some of the victims’ relatives expressed deep ambivalence about the development, as well as frustration at the slow-moving proceedings. “No matter how many letters they send, until I see it, I won’t believe it,” said Jim Riches, who lost his firefighter son in the attacks.