Boston bomb accused pleads not guilty

Boston Marathon bomb suspect Dzhokhar Tsarnaev has pleaded not guilty to all charges in his first court appearance, as blast victims looked on.

Tsarnaev, 19, faces 30 counts of using a weapon of mass destruction in the two 15 April blasts that killed three, including an eight-year-old boy.

He appeared in shackles and an orange prison suit, and replied not guilty as the charges were read to the court.

Prosecutors could press for the death penalty for 17 counts.

The suspect has also been charged over the death of a fourth person, a university police officer, who was allegedly shot dead by Tsarnaev and his brother Tamerlan in the days after the attack.

Mr Tsarnaev's older brother Tamerlan, 26, was killed days after the attack during a massive police operation.

More than 260 people were injured when two pressure cooker bombs packed with nails, ball bearings and other shrapnel were detonated at the finish line of the Boston Marathon.

The bombing was the worst mass-casualty attack on US soil since 11 September 2001.