Though the explosives in all four incidents were of three different designs, the Department of Homeland Security found that the bomb-maker followed guidelines featured in Inspire, an online magazine published by al-Qaeda in the Arabian Peninsula.
四起事件中的炸药虽采用三种不同的设计，但国土安全局发现炸弹制造者遵照基地组织阿拉伯半岛分支网络杂志《灵感（英语：Inspire (magazine)）》的指南。