We had spent so many days engrossed in the minutiae of ballistics, in awe of the ability of the FBI to find a discarded backpack in a landfill, in debate over the phenomenon of radicalization and whether Dzhokhar Tsarnaev was the dupe of a controlling older brother, distracted by the horse race nature of daily testimony, that it took Dr. Jennifer Hammers to remind everybody Thursday what this trial is really about.
Hammers performed the autopsy on Krystle Campbell, one of the three people murdered near the finish line of the Boston Marathon. Campbell was killed by the bomb that Tamerlan Tsarnaev left outside Marathon Sports.
Bill Weinreb, the prosecutor, asked Hammers to explain to the jury how and why Campbell died.
Her death was a homicide, Hammers said. The cause of death were blast injuries to her torso and legs.
If Hammers had left it at that, maybe the jurors and everybody else in the courtroom would have been thinking about all those other things that have flitted in and out of federal court the past week. But she went on, in clinical detail, and her words cut through everyone in the courtroom the way her scalpel cuts through flesh, looking for answers.
“She had singeing on the hair on the back of her head,” Hammers said.
There was a pellet, a BB, embedded in the back of her ear.
Her tongue was bruised.
The back of her right upper arm was burned. She had a third-degree burn on her back.
“Most of her injuries were on the back of her right arm and her lower legs,” Hammers said.
Some of the wounds were gaping, up to 10 inches long.
Her left foot was fractured. Her left thigh bone was broken.
“Is that painful?” Weinreb asked.
“Very painful,” Hammers replied.
BBs, the shrapnel from the bomb, were embedded in her skin, in her clothes.
“Some of them were very deep,” Hammers said.
As the jurors looked at their monitors, photographs of Campbell’s autopsy were shown.
Some of the jurors looked ill. Others looked mad. Still others were crying.
“This is a very close up picture of some of the wounds on the back of her leg,” Hammers said. “The smaller wound has a piece of flat metal embedded.”
She opened some evidence envelopes. They contained swabs she used to collect foreign material from the wounds on Campbell’s body.
“What is that?” Weinreb asked.
“Three larger flat pieces of metal,” Hammers replied.
At one point, Tsarnaev appeared to turn to catch a glimpse of all this on the monitor being watched by one of his lawyers, David Bruck. Judy Clarke, another of his lawyers, put her hand on his shoulder and Tsarnaev stopped looking.
Hammers explained that Campbell died because blood vessels in her legs were cut and she lost a significant amount of blood.
“How long did it take her to bleed out?” Weinreb asked.
At this point, Bruck jumped up and asked for a sidebar conference. It was almost like a basketball coach calling a timeout after the other team goes on a run.
But after the sidebar, Weinreb posed the question again.
“What’s your best estimate on how long she lived?”
“She would have been able to survive from seconds to approximately a minute or so,” Hammers said.
But Weinreb wanted to be more specific, so he asked Hammers if there is a way to estimate whether it was closer to a few seconds or a minute.
Yes, Hammers replied. People with injuries to the smaller blood vessels of their body live longer, she said. The injuries to Campbell’s legs put her in that category.
“So she could have lived up to a minute?” Weinreb asked.
“Yes,” Hammers said.
So, at the end of the 14th day of testimony in the trial of Dzhokhar Tsarnaev, the jurors who will decide his guilt and then whether he is put to death or spends the rest of his life in prison were left with this image: Krystle Campbell, a 29-year-old woman so loved by her friends that she was a bridesmaid 17 times, lying on the sidewalk of Boylston Street outside Marathon Sports, her body ripped apart.
The image that will stay with them until testimony resumes Monday, an image that may stay with them the rest of their lives, is Campbell, dying slowly and painfully, her blood spreading across the sidewalk as her wounded friend Karen Rand McWatters holds her hand and feels it go limp.
And here’s something Tsarnaev can chew on over the weekend: on Monday, the next time he’s in court, there will be two more doctors ready to testify about what the bomb he left outside the Forum restaurant did to the bodies of 23-year-old Lingzi Lu and 8-year-old Martin Richard.
Kevin Cullen is a Globe columnist. He can be reached at email@example.com