Boston bomber Dzhokhar Tsarnaev, sentenced to death on Friday, appeared to be on course for a normal American life before he launched his attack on crowds watching a marathon.
The man who called himself Jahar lived outwardly as an undisciplined but well-adjusted university student. He liked to party, narrated his exploits on Twitter and occasionally smoked marijuana.
There was no public expression of Islamist extremism, no cause for alarm. He became a naturalized US citizen a year before the April 15, 2013 attacks and was studying at the University of Massachusetts. But, in a tale of the American dream gone seriously wrong, the boy who emigrated with his family from Kyrgyzstan in 2002 has now been sentenced to death for carrying out one of the bloodiest attacks on US soil since September 11.
Two bombs planted in backpacks at the finish line of the Boston marathon killed three people and wounded more than 260, plunging the northeastern city into mourning.
He was convicted on all 30 counts relating to the bloody attacks.
Watch: How the Tsarnaev death sentencing in Boston marathon bombing unfolded
US authorities say Tsarnaev and his older brother Tamerlan, who was shot dead by police on the run, built the bombs using instructions from an online al Qaeda magazine in English.
When Tsarnaev was arrested four days later, seriously wounded, his photograph -- of a 19-year-old with unruly, shaggy hair -- spread quickly all over the world.
Today the dark hair is the same, but his face has grown gaunt. Flanked by his five lawyers, he sat through most of his trial emotionless, rarely talking to his attorneys and not publicly uttering a word.He sat still when the judge explained to him he could be sentenced to death over the marathon attacks and the killing of a police officer three days later.
Boston Marathon bomber Dzhokhar Tsarnaev is shown in a courtroom sketch after he is sentenced at the federal courthouse in Boston, Massachusetts. (Reuters Photo)
The only flash of emotion the jury saw was from a screenshot of Tsarnaev defiantly brandishing his middle finger to a surveillance camera before his first court appearance.
His lawyers argued it was a meaningless gesture from a bored young man, but prosecutors used the video to paint him as a ruthless and remorseless killer.
Tsarnaev was not handcuffed nor were his feet shackled during the trial. When the judge has asked him to stand up to show himself to the jurors, he did so mechanically and quickly sat back down.
On the first day, he seemed unwilling to look prospective jurors in the face, keeping his eyes fixed on the ground or the judge.
In subsequent court sessions, he seemed more assured, but frequently touched his hair, knotted his hands or tilted his head. He flicked his eyes from floor, to judge, then back to his feet.
Since his arrest, he has been held in near isolation at Fort Devens prison hospital 70 kilometers (40 miles) from Boston.
All visits are monitored and only his lawyers and sisters are permitted to see him. No physical contact is allowed.
His father, who comes from Chechnya, and his mother from Dagestan left the United States to return to Russia before the attacks and have apparently never come to visit.
Phone calls are limited to immediate family and monitored by the FBI. He is allowed to write one letter a week to his family.
As a student living at the University of Massachusetts in Dartmouth, south of Boston, he was by all accounts well integrated, loving his cat and driving his own car. Only a message inside the boat where Tsarnaev was arrested offers a glimpse into the possible motive behind the crime: "The US government is killing our innocent civilians... We Muslims are one body... Stop killing our innocent people and we will stop."
It was a shift in tone from a Twitter message he wrote two days after the attacks: "I am a stress free kind of guy."
Acquaintances remember him as a quiet young man, who appeared to defer to older brother Tamerlan.
The son of the landlord of an apartment rented by the Tsarnaevs described his impressions of Dzhokhar at age eight, when the family first came to America. "He was very sweet," said Sam Lipson, a witness at the trial. "He was a little shy."
Other witnesses recalled that when Tamerlan was around, Dzhokhar hardly spoke.
"He was like a puppy following his brother," said John Curran, Tamerlan's former trainer.