In this courtroom sketch, Assistant US Attorney Al Chakravarty is shown pointing to defendant Dzhokhar Tsarnaev during closing arguments in Tsarnaev’s federal death penalty trial in Boston. Photograph: Jane Flavell Collins/AP Photo 1:15

The surviving Boston Marathon bomber was a partner with his co-conspirator brother in a “cold, calculated terrorist act” intended to punish America f(...)

A courtroom sketch shows accused Boston Marathon bomber Dzhokhar Tsarnaev (left) and Judge George O’Toole (top) listening as bombing victim Richard Martin’s father Bill (top right) testifies, during Tsarnaev’s trial at the federal courthouse in Boston, Massachusetts.  Photograph: Jane Flavell Collins/Reuters

Moments after being blasted into the air “like a rocket” in the Boston Marathon bombing, nurse Jessica Kensky saw that her husband’s leg had been blo(...)

Dignitaries including US vice-president Joe Biden, survivors and first responders participate in a flag-raising ceremony at the marathon finishing line in Boston, Massachusetts, yesterday, on the first anniversary of the Boston Marathon bombings. Photograph: Reuters/Brian Snyder

Boston paused in silence at 2.49pm yesterday to remember the moment a year ago when three people were killed (...)

Defense attorneys Miriam Conrad (left) and Judy Clarke  flank Dzhokhar Tsarnaev in court in Boston, Massachusetts today in this  court sketch. Photograph: Jane Rosenberg/Reuters

Accused Boston Marathon bomber Dzhokhar Tsarnaev pleaded not guilty to committing the worst mass-casualty attack on US soil since 9/11, a crime that c(...)

A Massachusetts state police officer keeps watch hours after Boston Marathon bombing suspect Dzhokhar Tsarnaev was transferred to a federal medical detention centre at Fort Devens yesterday. Photograph: Gretchen Ertl/The New York Times

Dzhokhar Tsarnaev (19) left Beth Israel Deaconess Medical Centre overnight on Thursday into Friday morning and was moved to a medical ce(...)

US vice president Joe Biden speaks to police officers at memorial services for Massachusetts Institute of Technology Patrol Officer Sean Collier.

The brothers suspected of bombing the Boston Marathon were described as “twisted, perverted, cowardly, knock-off jihadi(...)

Police with guns drawn search for a suspect in Watertown, Massachusetts, early yesterday. Photograph: Mario Tama/Getty Images

A police helicopter circled overhead. The sky buzzed and blue lights flashed from the ground on the campus of Massachusetts Institute of Techno(...)