The perpetrator of the anthrax letters in the United States has yet to be found and there has been a lot of conflicting information published about the quality of the anthrax powder and the identity of the possible perpetrator(s).
美国发生的炭疽信案件的犯罪人仍未找到，发表的有关炭疽粉质量和可能犯罪人身份的许多信息都莫衷一是。