Boston Marathon bombing suspects Tamerlan and Dzhokhar Tsarnaev picked up an arsenal of explosives and weapons from the family’s Cambridge apartment to arm themselves for their “murderous spree” after the FBI published photos of them on April 18, 2013, federal prosecutors allege.
Within hours, MIT police Officer Sean Collier was shot to death in Cambridge, and Tamerlan Tsarnaev was fatally injured in a confrontation with police in Watertown in which the brothers used a handgun and hurled homemade bombs at officers, federal prosecutors said.
The details about the alleged role the family’s Norfolk Street apartment played in the terrorist attack on the Marathon were disclosed by US Attorney Carmen M. Ortiz’s office in court filings made public late Monday. In the documents, prosecutors defended the search of that apartment and Dzhokhar Tsarnaev’s dormitory room at the University of Massachusetts Dartmouth.
The two brothers are accused of committing the April 15, 2013, bombings in Boston that killed three people and injured more than 260. They are also accused of killing Collier on the night of April 18, 2013.
Tamerlan Tsarnaev was killed early April 19, 2013, in the Watertown confrontation, shot by police and run over by his own brother as he fled in a car. Dzhokhar Tsarnaev was captured later that same day and is awaiting trial on charges that could bring him the death penalty.
Authorities learned the Tsarnaevs’ identities only after Tamerlan Tsarnaev was fingerprinted at the hospital where he was taken after he died, prosecutors revealed in the filings.
Later that day, they closed down the Norfolk Street neighborhood and searched the apartment where the Tsarnaev family had lived for many years, including the time Dzhokhar had attended and graduated from Cambridge Rindge and Latin High School.
What authorities found has been largely kept under seal. But the new filing provides glimpses into what they discovered during two searches of the Cambridge address and three visits to Dzhokhar Tsarnaev’s dorm room.
In the Cambridge apartment where Tamerlan Tsaranaev was then living with his wife, Katherine, authorities allege the brothers’ weapons cache included at least six improvised explosive devices, a handgun, and other weapons. Prosecutors allege the arsenal was used in the violent Watertown confrontation.
Among the 100 items taken from the Norfolk Street apartment, prosecutors said, was a Russian dictionary that “contained a prayer card bearing handwritten references to convicted terrorist supporter Tarek Mehanna and the late Al Qaeda propagandist Anwar al-Awlaki.’’
Awlaki was killed by a US drone strike in Yemen.
Mehenna, a Sudbury native, was convicted in December 2011 of conspiring to provide material support to terrorists, conspiring to kill in a foreign country, and lying to authorities in a terrorism investigation. Prosecutors said Mehanna traveled with an associate to Yemen in 2004 to join a terrorist training camp and ultimately attack American soldiers in Iraq, but the plan failed.
Investigators also recovered an e-mail Dzhokhar sent to his mother before the slaying of Officer Collier.
In the e-mail, only a portion of which was made public, Dzhokhar told his mother that he loved her and ended with the promise that they would see each other
“Inshallah (i.e. God willing) if I don’t see you in this life I will see you in the akhira (i.e. afterlife),’’ prosecutors wrote.
Prosecutors want US District Court Judge George A. O’Toole Jr. to allow them to use the evidence seized during the searches against Tsarnaev, who is facing the death penalty, and to reject a defense request to hold a hearing on how agents obtained the information.
Prosecutors also said that during the searches of the dorm room they seized a pizza box with a pizza receipt and two books, one titled “Muslims in the West’’ and the other, “Soldiers of God.’’
The pizza box proved he lived there, and the books may show his motivation, prosecutors said.
Six weeks after school ended in 2013, UMass Dartmouth personnel entered Tsarnaev’s room and emptied it while an FBI agent looked on.
UMass Dartmouth, as landlords, was preparing the room for its next student, prosecutors said.
School officials collected 21 items that were then seized by the FBI, including a piece of gray plastic from an electronic remote control device, two notebooks with the name Timir Mugynov, and a single copper-colored BB pellet.
Martin Finucane of the Globe staff contributed to this report. Milton J. Valencia can be reached at mvalencia@
globe.com. Follow him on Twitter @miltonvalencia. John R. Ellement can be reached at firstname.lastname@example.org. Follow him on Twitter @JREbosglobe.