The terrorist responsible for multiple explosions in New York and New Jersey, Ahmed Khan Rahami, bought explosives supplies through website eBay using his name as his username, the FBI revealed in an indictment published Wednesday.

Rahami navigated eBay with the username “ahmad rahimi,” an alternative spelling of his real name, according to FBI Special Agent Peter Licata, and bought a number of legal items commonly used in home bomb-making. Among those purchases were citric acid, a circuit board, fireworks electric igniters, and lead ball bearings, all found in the construction of the explosives used in Rahami’s terror attacks over the weekend. The items were purchased in June and August 2016, indicating that Rahami had planned his bombings for months.

The items were shipped to an unnamed business in Perth Amboy, New Jersey, a half an hour drive from Elizabeth, where authorities believe Rahami lived part-time with his family. Rahami allegedly worked at the Perth Amboy business until September 12, and also had an apartment in the city rented in his name.

The indictment, which contains multiple charges for the use of a weapon of mass destruction and attacking a public transportation hub, also notes that Rahami used two mobile phones as remote controls for detonating the bombs in the Manhattan neighborhood of Chelsea and the shore town of Seaside Park, New Jersey. Both of those devices appear to have been purchased at the business where Rahami worked.

At least one of the devices was registered in the name of a Rahami family member. Relatives of Rahami’s were stopped Sunday night and interrogated by police, leading to Rahami’s arrest Monday.

Law enforcement officials have repeatedly asserted that Rahami appears to have acted alone, though they have yet to explain numerous suspicious facts regarding Rahami’s family. The FBI indictment notes that a video found on the phone of a relative of Rahami’s depicts Rahami testing an explosive in the family’s backyard in Elizabeth. “Laughter” can be heard after the explosion, though the report does not indicate how many people can be heard laughing.

Rahami’s wife, identified as Asia Bibi Rahami, fled to her native Pakistan days before the attack. Rahami’s mother is also abroad. Law enforcement sources say they are working to bring Rahami’s wife back to the United States for questioning.

Rahami is believed to be responsible for three bombings between September 18 and September 20. The first exploded in Seaside Park, New Jersey, targeting a charity 5K race; the second exploded in the Manhattan neighborhood of Chelsea and injured 31 people. The third explosion occurred in Elizabeth, where a law enforcement robot accidentally detonated one of the five explosives left in a backpack by the city’s train station.