The alleged perpetrator of the attacks in Boston Dzhokhar Tsarnaev Thursday appeared in public for the first time in 17 months, during a brief hearing before his trial due to begin on 5 January.

Black sweater, gray pants, curly beard and hair unruly, Tsarnaev, 21, slender build, sat between his two lawyers in the courtroom of the federal court in Boston (Northeast US) packed for the occasion. He calmly answered questions from Judge George O’Toole, including asking if he was represented by his lawyers.

The technical hearing, during which the judge referred to the leaks to the press and announced continued in private discussions about jury selection, lasted less than half an hour.

At its very end a woman shouted in Russian, then in English “Stop killing innocent people.” The victims’ families, face often severe, were separated from the rest of the public.

In better health liable to the penalty death for the double attack that had overshadowed the famous Boston Marathon April 15, 2013, Tsarnaev, young Muslim Chechens, had not been seen since he pleaded not guilty on July 10, 2013. He was visibly suffering serious injuries dating from his arrest. On Thursday, he seemed much healthier.

He is accused of having detonated simultaneously with his brother Tamerlan two homemade bombs in pressure cookers hidden in backpacks, near the marathon finish line which is held thousands of spectators. This double attack, the most serious since the September 11 attacks in the United States, had left three dead and 264 wounded an extremely popular sporting event and reviving fears of terrorism.

Tamerlan Tsarnaev was killed four days Later during a confrontation with police. Dzhokhar was arrested on 19 April in the evening, hidden in a boat stored at the bottom of a garden, seriously injured. Originally scheduled on November 3 trial must finally opened on January 5 with jury selection, which could take weeks. The trial is expected to last him two to three months.

Tsarnaev is being held in prison hospital at Fort Devens, some 70 km from the Boston court. It is there virtually isolation according to his lawyers, due to special restrictions in August 2013 by the Minister of Justice Eric Holder.

These “special administrative measures”, confine him to his cell according to his lawyers, and limit his visits to his only immediate family – his sisters – and its defenders. They also limit his telephone conversations, his letters and prohibit all contact with the media.

Thirty charges are brought against him, including use of a weapon of mass destruction that caused the death and attack in a public place causing death.

On an inner wall of the boat in which he was found in a garden of Watertown, a suburb of Boston, Dzhokhar Tsarnaev, who was a student then and seemed well built, had given a kind of explanation for the attacks.

The US government is killing our innocent civilians. I cannot bear to see the evil go unpunished. We Muslims are one body, you hurt the one of us, you do us harm to all. I do not like killing innocent civilians. Islam forbids but stop killing our innocent and we’ll stop,” wrote Tsarnaev.

Arrived in Boston at the age of 8 with his family from Dagestan, Dzhokhar Tsarnaev, naturalized American in 2012, was deeply influenced by his family history, tossed, child, North Caucasus Kyrgyzstan, before immigrating to the United States in 2002.

The two brothers, who seem to have acted alone, had prepared their bombs from instructions of the Inspire online magazine, a publication of al-Qaeda, according to prosecutors.