Tamerlan and Dzhokhar Tsarnaev initially planned their Boston bombing attack for the Fourth of July but changed the date when the bombs they built were ready much earlier than expected.

Van carrying Tamerlan Tsarnaev arrives at a North Attleboro, Mass. funeral home (WBZ TV)

CNN reports Dzhokhar told investigators of their plans to carry out a suicide bombing on the Fourth of July but changed their plans to the Boston Marathon only a couple days before the April 15 race.

He did not mention a specific event on the Fourth but the Boston Pops perform a concert along the Charles River every July 4th that attracts upwards of 500,000 culminating with a rousing rendition of the 1812 Overture set to a fireworks display.

The Boston Marathon bombing which killed 3 at the finish line of the race in Boston's Back Bay and an MIT police officer during a manhunt. Hundreds were injured in the blast and lost limbs.

FBI "Skeptical" Of Wife's Story

Katherine Russell (WLNE TV)

It is unclear if Tamerlan's wife, Katherine Russell, who has told of working long hours, was aware of her husband's activity in their Cambridge apartment according to CNN. She went to stay with her parents in Rhode Island shortly after he was identified as a suspect and refused to claim his body.

The New York Times
reports that investigators are "skeptical" of her claims she had no knowledge of the plans and are investigating her possible role in helping the brothers in the days after the bombing.  She is no longer co-operating with police according to the Times.

Russell's lawyer has said that she was in "absolute shock" when she discovered his involvement in the bombing.

Today may also bring an official cause of death for Tsarnaev. That information could not be released until a certificate of death was filed with the City of Boston. Department of Public Safety spokesman Terrel Harris said Thursday a funeral home retained by Tsarnaev's family picked up the 26-year-old's remains.

WCVB TV reports Tamerlan's body was taken to a Worcester, Massachusetts funeral home after being claimed by his family yesterday in Boston.

The Graham Putnam and Mahoney Funeral Parlors confirmed they are handling arrangements for the 26-year-old.

After a hearse believed to be carrying Tsarnaev's body departed Boston, television stations reported that their helicopters followed it to the Dyer Lake Funeral Home in North Attleboro. About 20 protesters gathered outside the funeral home. An Associated Press photographer later saw a hearse leaving the home escorted by two police cars.

Dyer-Lake Funeral Director Tim Nye told The Sun-Chronicle newspaper late Thursday that the body was only brought to his funeral home temporarily and was transported to another facility, but he didn't say where.

"He is not at our funeral home and we won't be handling final arrangements," Nye said.

The Associated Press contributed to this story.