Abu Khalid Abdul-Latif, also known as Joseph Anthony Davis, of Seattle, and Walli Mujahidh, also known as Frederick Domingue Jr., of Los Angeles, were arrested Wednesday night after they arrived at a warehouse garage to pick up machine guns to use in the attack, an FBI agent wrote in a criminal complaint filed in U.S. District Court.
Authorities said they had been watching Abdul-Latif, 33, and Mujahidh, 32, and the weapons transaction to prevent the attack.
The suspects did not know that the weapons had already been rendered inoperable and posed no risk to the public.
Law enforcement was first alerted to the plot when someone contacted the Seattle Police Department saying he had been approached about participating in the attack and supplying firearms. That person agreed to work with officials to monitor the suspects.
The building, the Military Entrance Processing Station on East Marginal Way in Seattle, also houses a daycare. Recruits for all military branches are screened and processed there.
In audio and video recordings, the men discussed the plot at length, discussing how to time their attack at military recruits, such as by tossing grenades in the cafeteria, the complaint said.
Mujahidh voluntarily spoke with investigators after the arrests and confessed, the complaint said.
The men were scheduled to make initial court appearances Thursday on terrorism and firearms charges.
The Associated Press contributed to this report.