The theory that Tsarnaev detonated the two backpack bombs at the finish line of the race was bolstered by the weekend revelation that he had said in text messages he was planning to join up with militant Muslim jihadists.
The Boston Herald said Sunday the collection of texts, which had been intercepted by Russian intelligence agents, did not include any smoking guns linking Tsarnaev to the Boston bombings; however it would explain why Moscow decided to tip off their American counterparts that Tsarnaev was worth keeping an eye on.
"Each text message may not have shown anything, (but) it is still important to put all the pieces together," Cedric Leighton, former deputy director of training at the National Security Agency, told the newspaper.
"Some little snippet of information could make all the difference."
The FBI found no evidence Tsarnaev was a threat and was not monitoring him when he and his younger brother, Dzhokhar, allegedly planted the bombs.
Tamerlan was killed by police a few days later. His remains were left in limbo when cemeteries in the Boston area refused to allow his burial.
The Chechnya-born Tsarnaev's final resting place was seemingly settled last when an anonymous donor offered to have them interned in Doswell, Va.
Caroline County Sheriff Tony Lippa told the Herald the necessary paperwork had been filed so the burial could not be halted. He added his department would not provide any special security to prevent vandalism at the cemetery.
"The Caroline County Sheriff's Office cannot ... divert our limited resources towards the protection of a single grave site, especially one belonging to that of a terrorist," said Lippa in a written statement.
Dzhokhar Tsarnaev was wounded and is in custody.