A spokesperson for the U.S. attorney's office and the FBI declined to comment and authorities said no decision has been made on whether to eventually bring charges while prosecutors concentrate on the trial of Dzhokhar Tsarnaev, Russell's brother-in-law.
A few weeks earlier Tamerlan Tsarnaev had gone to a fireworks store in New Hampshire and bought 48 mortar shells, also used in the bombs. At the fireworks store, Tamerlan had asked for the "biggest and loudest" fireworks available and spent roughly $200, according to court documents.
"To live in a small apartment and buy five pressure cookers and have all those explosives obviously just does not make sense -- something other than cooking was going on," said former FBI special agent and ABC News consultant Brad Garrett.
That Special Agent Brad Garrett, mind like a steel trap.