Later on -- after El Khalifi had purchased nails, glue and cell phones for use in what he thought was an separate planned al-Qaeda attack against a military installation -- he decided that he'd rather go on a "suicide/martyrdom operation in which he would blow himself up in the United States Capitol Building," according to an FBI affidavit.
In mid-January, El Khalifi allegedly traveled to a quarry in West Virginia where undercover agents posing as al-Qaeda members let him dial a cell phone number that he thought would detonate a bomb placed in the quarry that was similar to one he believed would use in the U.S. Capitol building. The bomb went off, and on the way back home, El Khalifi said he wanted Feb. 17 to be the date of his martyrdom operation, according to the affidavit.
He allegedly surveilled the building and decided not to make a martyrdom video because he didn't want people to know who conducted the attack.
On Friday morning, El Khalifi allegedly took possession of what he thought was a MAC-10 automatic weapon in a vehicle parked in an unidentified garage near the U.S. Capitol, put on the vest containing what he thought was a functioning bomb and "walked alone from the vehicle toward the United States Capitol, where he intended to shoot people and detonate the bomb."
El Khalifi was arrested before he left the garage.