Boston Marathon Bombing Trial: Troopers Tell of Explosive Shoot Out With Suspects

A State Trooper talked about the "improvised grenades" used by the brothers.

ByABC News
March 18, 2015, 12:48 PM

— -- A jury deciding the fate of Boston Marathon bombing suspect Dzhokhar Tsarnaev was shown today the home-made bombs that Tsarnaev and his brother allegedly hurled at police during an intense manhunt for the suspects.

Massachusetts State Police Trooper Robert McCarthy, a member of the bomb squad, told the jury he heard repeated calls over the radio several times about the brothers "throwing bombs at us."

"We heard what we believed to be some type of explosive and saw smoke in the street lamps," McCarthy said.

When the shooting stopped, McCarthy said he found "potential pipe bombs in the middle of the road."

Jurors were shown two unexploded pipe bombs, one that McCarthy said was "very heavy" and curved so it wouldn't roll when it landed. "It was full" of explosive powder, he said.

"It's basically [a pipe] elbow, approximately two inches in diameter. It still has one end-cap on it and one end-cap removed," he said, noting that the devices are more like "improvised grenades," because "it won't roll away. It will land and stop."

A second device the jury saw was straight, also "full" of explosive powder, according to McCarthy. "This pipe is also lined with BBs," he said.

Shrapnel from the bombs that the defendants threw during their climactic battle with police were found everywhere: inside cars, on front lawns, in backyards, on roofs, inside homes, McCarthy said, and slugs from Dzhokhar Tsarnaev's gun were embedded in walls.

On the floorboard behind the driver's seat in the Mercedes SUV that the Tsarnaev brothers allegedly carjacked, investigators found what they thought was another bomb, McCarthy said, describing it as "basically a Tupperware box that had a fuse coming out of it" and "two to three pounds" of explosive powder.

As it was held in front of jurors, McCarthy described it as "another improvised explosive device."

The court also released today the questionnaire used during jury selection. It included the question "Have any of your siblings tried to influence your direction in life or your major life decisions?"

Defense lawyers have asserted that Tsarnaev was under the influence of his older brother, Tamerlan Tsarnaev, and that he was not himself a committed terrorist.

Potential jurors were also asked in the questionnaire whether they had strong opinions about Islam or whether the U.S. "acts unfairly toward Muslims."

Tsarnaev faces the death penalty after he and his brother allegedly placed twin bombs at the finish line of the 2013 Boston Marathon, killing three people and injuring 260 others. Tsarnaev has pleaded not guilty to the 30 counts against him, including charges of using a "weapon of mass destruction resulting in death," but his defense attorney has said that he participated in the bombing.