Federal agents recovered the backpack in the New Bedford, Mass., landfill. It contained fireworks tubes that had been emptied of their powder.
According to the FBI,
the found fireworks were from a store other than the Phantom Fireworks shop in Seabrook, N.H., which disclosed a purchase by Tamerlan Tsarnaev in February.
The FBI was checking on sales with other dealers in the area.
...
Authorities say the three friends who have been hit with obstruction of justice and lying charges also took Dzhokhar Tsarnaev's laptop computer from his dorm room
but did not throw it away and have since given it to the FBI.
http://usnews.nbcnews.com/_news/201...-plotted-july-4-attack-investigators-say?lite