May 2, 2013 7:21 AM by Jeff Langan
BOSTON (AP) - Authorities say hours before one of the Boston Marathon suspects and his brother allegedly gunned down a campus police officer, he exchanged a series of text messages with a friend.
Those texts set off events that led to three friends of Dzhokhar Tsarnaev being charged in connection with his case on Wednesday.
An FBI affidavit says the trio removed the bombing suspect's backpack from his dorm room at the University of Massachusetts Dartmouth three days after the April 15 attack that killed three people and injured more than 260.
Authorities say one of them later threw the backpack in the garbage, and it wound up in a landfill, where it was discovered by law enforcement officers last week. The backpack contained fireworks that had been emptied of their gunpowder.