After the three men returned to Kadyrbayev's and Tazhayakov's apartment with the backpack and computer, they watched news reports featuring photographs of Tsarnaev.
The FBI affidavit said Kadyrbayev told authorities the three men then "collectively decided to throw the backpack and fireworks into the trash because they did not want Tsarnaev to get into trouble."
Kadyrbayev said he placed the backpack and fireworks along with trash from the apartment into a large trash bag and threw it into a garbage bin near the men's apartment.
Meanwhile, Tamerlan Tsarnaev's relatives will claim his body now that his wife has agreed to release it, an uncle said. The body of Tsarnaev, 26, has been at the medical examiner's office in Massachusetts since he died after a gunfight with authorities more than a week ago.
Amato DeLuca, the Rhode Island attorney for his widow, Katherine Russell, said Tuesday that his client had just learned that the medical examiner was ready to release Tsarnaev's body and that she wants it released to his side of the family.
Police said Tsarnaev ran out of ammunition before his 19-year-old brother dragged his body under a vehicle while fleeing the scene. His cause of death has been determined but will not be made public until his remains are claimed.
"Of course, family members will take possession of the body," uncle Ruslan Tsarni of Maryland said Tuesday night. "We'll do it. We will do it. A family is a family."
He would not elaborate. Tsarnaev's parents are still in Russia, but he has other relatives on his side of the family in the U.S., including Tsarni.